As a result of the accident in which he gained his powers, the Molecule Man has a series of jagged scars radiating from the bridge of his nose in a lightning-like pattern. He can use his powers to conceal the scars at will.
Owen Reece, was born in Dinosaur, Colorado but eventually moved to Brooklyn, New York. As a small and frail child he was raised by a coddling and over protective mother.  By his own accounts Owen has claimed contrary to this, stating that his mother gave birth to him late in life and despised him.  He has also stated that he was picked on in high school.  While growing up, Owen developed a love for magicians and aspired to be one, but this childhood dream did not come to pass.  As an adult he ended up working for the ACME Atomics Corporation and worked there for the next twelve years. Living a life beneath everyone's notice, Reece hoped for the day when he would be recognized by his peers for his hard work. While attempting to fix an atomic powered device when a trillion-to-one accident occurred bombarding him with radiation and transforming his body.  The accident also caused a "pin prick" hole between Earth's dimension and another. Allowing the being who would eventually become known as the Beyonder to become aware of a universe teeming with life, an event that would have an impact of Owen's life many years later.  Soon Reece found that he could control the molecular structure of nearly anything. When he was fired from his job due to the accident, Reece decided to use his powers to take over the world. He then dubbed himself the Molecule Man and plotted to take over New York City.  Due to his psychological problems and low self-esteem, stemming from his mother, Owen subconsciously placed limitations on his powers, such as being incapable of affecting the molecules of living things. Initially he also had to use a "magic wand" to focus his powers as well.  Owen has stated that the wand was initially used due to his past infatuation with magicians. 
Sensing the danger that the Molecule Man posed, Uatu the Watcher contacted the Fantastic Four and warned them of the threat, transporting them to face their foe as he threatened the city of New York from Time Square. The Fantastic Four initially were unable to match the powers of the Molecule Man. However their leader Mr. Fantastic was able to deduce that the Molecule Man could not alter the molecules of living things. Seeking refuge at the home of their ally, the blind sculptress Alicia Masters, the Fantastic Four had themselves covered in a thin layer of plaster and posed as statues while Alicia signaled the Molecule Man to her home. Thinking the FF were really statues made by Alicia, the Molecule Man attempted to use his powers to use the "statues" as weapons. However he soon realized his error and was ambushed by the Four. When Reed Richards confiscated the Molecule Man's wand, the Watcher swooped in and contained him, telling the Four that their foe would never menace Earth again. 
Son of Molecule Man
The Watcher placed the Molecule Man in another dimension where time moved much more rapidly hoping that the Molecule Man would die of old age. Some records indicate that the Watcher was able to reinforce the mental blocks on Owne's powers, however other sources refute this. Whatever the case, Owen apparently used his powers to create a "son" and a new wand. Already grown too old to get his revenge, Owen constructed a device that would allow his "son" to recreate the accident that gave the Molecule Man his powers. Unknown to the "son" the consciousness of the Molecule Man had been transported into the wand that channeled his powers after the original Molecule Man had died.  This iteration of the Molecule Man no longer had the limitations of his predecessor. However when attempting to use his powers to transport himself to New York City, he appeared in the Florida Everglades in the Nexus of All Realities near the town of Citrusville. He appeared before the defender of the Nexus, the muck-monster known as the Man-Thing. Initially frightened by the creature, the Molecule Man dropped his wand and realized that unless he was holding it, his new body would begin to rapidly age.
The Molecule Man then attempted to leave the swamp but became lost. He then happened upon the Man-Thing again along with the Fantastic Four's Thing, who happened to be in that area searching for the Man-Thing. As a cruel jest, the Molecule Man reverted them back to human form before attempting to escape the swamp again. Reece ended up in the town of Citrusville where the Ben Grimm and Ted Sallis attempted to stop his rampage. The Molecule Man reverted them back to their monstrous forms and tried to pit them against each other. During the battle the Thing tossed a clump of the Man-Thing's muck at the Molecule Man, knocking his wand out of hand. It was too far out of his reach and before Owen could recover the wand, he aged so rapidly his body crumbled to dust. With the wand apparently powerless the Thing gave it to a young boy named Sanford as a souvenir. 
However the Molecule Man was not dead as his mind remained inside the wand, although it was dormant for many months. During this time the boy would play with is friends in the swamps near Citrusville, pretending to by a super-heroes and super-villains. During one afternoon of play, Sanford's friend Cynthia McClellan knocked it into the swamp. Going to retrieve it, Cynthia was chased by a alligator and ran into a pit of quicksand and seemingly drowned. However due to the radioactive properties of that particular area, Owen's mind was awoken from within the wand and used his powers to take control of Cynthia's body, saving her life. Trying to reshape her body into a muscular male form, Owen found that Cynthia's mind resisted the change preventing him from changing genders while in her body. Struggling with her mind, Reece attacked the home where Cynthia and her mother lived. When the heroic Avenger known as Iron Man happened a battle between the two began. However due to Cynthia's idol worship of the Golden Avenger, she forced the Molecule Man to flee. Later, the Molecule Man resurfaced as Iron Man was assisting in the reconstruction of the Omegaville and attacked. During the fight the wand was knocked out of Cynthia's hand freeing her from his control. However a nearby snake happened to attack the wand, allowing the Molecule Man to take possession of its body and transmute it into a humanoid form and resumed his attack. Iron Man tore the wand from the creature's hand and fought against his own possession long enough to hand the wand off to the passing Man-Thing. Since the Man-Think did not possess a mind the Molecule Man could not take control of its body and he was helpless as the Man-Thing wandered off into the swamps. 
Shortly thereafter, the super-villain known as the Klaw materialized in the Nexus of All Realities after his battle with the hero Ka-Zar. He appeared just moments after the Man-Thing discarded the Molecule Man's wand. Recovering, Klaw was immune to possession by Reece due to his inorganic form and agreed to help Reece obtain a permanent body. Learning of Reed Richard's Psi-Amplifier device they went to New York to use it on the Molecule Man's next host body. This body was fond in New York city when the pair happened upon a punch-drunk boxer and forced him to handle the wand allowing the Molecule Man to take control of him.  When they first broke into the Fantastic Four's Baxter Building headquarters the only person present was the visiting Impossible Man, whom they easily knocked out on a sneak attack.  When the Fantastic Four arrived, Klaw and the Molecule Man incapacitated the group and attempted to use the Psi-Amplifier. However the tide of battle began to change when the Impossible Man recovered from their previous attack and fought back. When the Molecule Man attempted to enter the Psi-Amplifier, Reed Richards had enough time to pull the power cable and the feedback caused Reece to retreat back into his wand freeing the boxer from his control. In the aftermath of the battle Reed Richards foolishly picked up the wand, laving himself totally open for the Molecule Man to take over his body.  Although Richards attempted to fight for control of his body, the Molecule Man proved too strong, and in order to save the lives of his teammates, Reed was forced to agree to relinquish control over to his foe. As the Molecule Man terrorized New York City, the Fantastic Four regrouped and attacked their foe anew. When Reed was knocked out in the fight this allowed the Molecule Man take full control and he attempted to unleash the full force of his powers to destroy his enemies. However this plan backfired as his powers could not affect their costumes which was constructed out of Unstable Molecules, causing sufficient feed back to shunt the Molecule Man's consciousness back into the wand and it dropped into a smoke stack where it was seemingly destroyed. 
However it survived and later when the smoke stack was cleared the ashes were dumped in a landfill in upstate New York. Months later a drunken homeless man accidentally came into contact with the wand during an encounter with the Micronaut known as Biotron. Although he was distracted by the fact that he was in possession of the body of an African-American, the Molecule Man sought to capture Biotron and examine him. Their battle took them to a nearby river where Biotron managed to down some power lines. The resulting electrical shock separated the wand from the Molecule Man's most recent host body and was swept down river. 
Sometime after this the wand was found by the Silver Surfer, but when the Molecule Man attempted to possess him, the Surfer's silver skin protected him and he discarded the wand. By this point, Owen decided to try and form a new body through the wand and was surprised when it worked to create him a new body. Restored to human form, the Molecule Man now had the same limitations he had before -- he could not affect organic matter. Intrigued by the Surfer the Molecule Man heard the space-faring heroes origin and was inspired by the tale of Galactus that Owen decided to consume the Earth. Creating a Galactus inspired costume, Owen easily over powered the Surfer and then went to the outskirts of Netoon, New Jersey and constructed a massive fortress to carry out this task. The Surfer then attempted to contact the Fantastic Four with his surf board. However when they were not home, the board was found by the Avengers who then freed the Surfer and went after the Molecule Man. With a barrier blocking their way, Earth's Mightiest Heroes smashed a hole large enough for their new member Tigra to slip through. She confronted the Molecule Man first, and finding that he was an emotionally stunted and insecure man, she promised to get to know him before deciding if she liked him or not. However this did not prevent the Molecule Man from striking back at the other Avengers when they arrived. He destroyed Captain America's shield, Thor's hammer, Iron Man's armor and the Silver Surfer's board before placing them in a crusher device and seemingly slaying them. 
The Avengers secretly survived thanks to the Surfer's Power Cosmic, however they were underpowered without Iron Man's armor and a mystical enchantment that forced Thor to revert to his civilian identity of Donald Blake once away from his hammer for more than a minute. Thinking her fellow Avengers were dead, Tigra attempted to murder the Molecule Man in his sleep but could not bring herself to do it. Despite the fact that they mostly lacked super-powers, the Avengers managed to attack the Molecule Man who fled in fear after being hit by Blake. Ultimately, Captain America incapacitated their foe. As the heroes debated on what to do with him, Tigra managed to convince Owen to get help instead of taking out his anger on the world, and instead use his powers to help people. These words got through the Reece who agreed and used his powers to restore everything to the best of his abilities and surrendered to the authorities promising to go see a therapist to help him with his troubled life. 
Owen soon found himself pulled back into the life of a super-villain when he was one of the many villains gathered by the Beyonder to battle a group of heroes in a conflict that later became known as the Secret Wars. He soon found himself aboard a ship along with Galactus, Latverian monarch Dr. Doom, the time traveler known as Kang the Conqueror, the robot Ultron, the Absorbing Man, Dr. Octopus, the Lizard, the AsgardianEnchantress, and the Wrecker'sWrecking Crew. Among the heroes gathered were members of the Avengers, Fantastic Four, the X-Men, the Hulk, Spider-Man, and the mutant terrorist known as Magneto. They witnessed as the Beyonder wiped out an entire galaxy and created a patchwork world dubbed Battleworld. They were suddenly attacked by Ultron who sought to destroy all living beings on their ship, but Dr. Doom convinced Owen to use his powers to lift Ultron up to Galactus, who drained the robot's energies making it inert. The Beyonder then spoke, telling the gathered super-humans to slay their enemies and they will be given what they desire most. Galactus and Dr. Doom attempted to confront the Beyonder directly and were rebuffed while the others were transported planetside. The villains soon found a headquarters and were reunited with Doom who suggested that they don't follow the Beyonder's decree and instead find a way to steal his power. When they refused, Doom attacked them and fled. Owen joined the other villains in hunting down Doom and found him and the gathered heroes meeting together and attacked. 
Doom escaped in the battle, and Owen and most of the others were forced to flee the battle when the heroes incapacitated and captured the Enchantress, Kang and the Wrecking Crew. When they returned to their base they found Doom waiting there with a body guard -- the reprogrammed Ultron and they were all forced to ally themselves with him and follow his scheme.  Dr. Doom discovered that the city of Denver, Colorado was also part of Battleworld and selected two women Mary "Skeeter" MacPherran and Marsha Rosenberg to endow with superhuman powers to bolster their ranks. MacPharran became the powerhouse known as Titania, and Rosenberg the plasma channeling Volcana. Volcana was instantly attracted to Owen and the found themselves forming a fast relationship. Recognizing the Molecule Man's great power, Doom made him his right-hand man and launched a counterattack on the gathered heroes at their headquarters freeing their captured comrades and forcing the heroes to flee.  Owen then used his powers to destroy their base and then levitated an entire mountain and dropped it on the heroes in an attempt to slay them. Similarly when Thor reappeared with the Enchantress, Owen and the others attacked and the thunder god was seemingly slain by Ultron. However the heroes survived these attacks and regrouped a nearby village near where Galactus. 
When Galactus summoned his massive world-ship Taa II to Battleworld to consume the planet, Doom sought to find a means of using the technology aboard the ship to defeat the Beyonder. Meanwhile Owen's relationship if Marsha began to blossom and when the Wrecking Crew attempted to bully the couple, Owen stood up for himself his display of powers frightening the power-houses and convincing them to respect Reece.  When Dr. Doom managed to board Taa II, he ordered his minions to create a series of volcanic eruptions to distract Galactus so Doom could continue to search the ship unnoticed. The Molecule Man joined Dr. Octopus, the Absorbing Man, and Titania on this mission. After they completed plugging up a volcano they were confronted by the X-Men, and during the fight Owen was savagely wounded by the X-Man known as Wolverine and they fled the scene.  When Marsha heard about Owen's injury, she convinced the Enchantress to teleport him to his side. They were once again attacked by the X-Men but this time they forced the mutants to retreat and when they returned to base, Owen was rushed to the medical lab to be healed.  While Owen was recovering the heroine known as She-Hulk attacked the villain's base after they seemingly killed her teammate the Wasp. This prompted the other heroes to come to her rescue. The villains were quashed in battle and the injured Molecule Man and his colleagues were captured and imprisoned at the heroes base.  While the villains were incarcerated Dr. Doom managed to first absorb the power of Galactus when he was forced to consume Taa II,  He then attacked the Beyonder head on and stole the majority of his powers. Doom then attacked the heroes base and in the ensuing chaos, the villains broke free and escaped.  Seeing Doom talking with the heroes, Owen became enraged as he believed that Doom was going to betray them. The Molecule Man swatted the heroes away and then confronted Doom directly. However now that he had gained the power of the Beyonder, Doom used his powers to remove the mental blocks that Owen placed on himself for years, allowing him to finally control all molecules. At Volcana's suggestion the villains regrouped at her Denver apartment to consider their next move. Deciding to return to Earth, Owen used his powers to erect an air tight dome around Denver and pull it into space.  While travelling through space, Owen began practicing his powers, using them to restore the stars destroyed by the Beyonder at the beginning of the Secret Wars. Owen stopped an attempted mutiny led by Dr. Octopus and then prevented the Enchantress from sacrificing Volcana to complete a teleportation spell, sending her back to Battleworld. While the villains escaped back to Earth, the heroes on Battleworld managed to defeat Doom. The Beyonder took back his stolen power and then returned them home as well. 
Secret Wars II
Back on Earth, Owen and Marsha decided to retire from being super-villains and moved in together in Marsha's Denver apartment. There they lived in relative anonymity and for many months until the Beyonder came to Earth seeking to understand the nature of human desire. Drawn to Owen, the Beyonder appeared to him in his apartment. Owen suggested that the Beyonder go out and seek out experience as that will teach him the meaning of desire, but suggested that he take on a new form than the composite form of the various heroes and villains he encountered on Battleworld. The Beyonder took his advice literally, taking on the form of Owen himself and running amok in Los Angeles where he battled Captain America, Iron Man, Magneto, the X-Men and the New Mutants before fleeing the scene.  Soon the Beyonder copied the form of Captain America and was brought under the wing of mobster Vinnie Cobo. He rose up to the ranks and eventually decided to make himself absolute ruler of the entire Earth down to the molecular level. This tampering was detected by the Molecule Man, who was himself immune, and he used his powers to prevent Marsha from being tampered with. Eventually the Beyonder found ruling the entire Earth unfulfilling and released it from his control. 
Deciding that the love of another was what he desired, the Beyonder returned to Owen for more advice. Owen tried to describe love to the Beyonder the best he could, relating to his relationship with Marsha. Taking this advice, the Beyonder once again attempted to accomplish his goals, leading to a disastrous courtship of the mutant singer known as Dazzler.  After a bout of depression,  the Beyonder decided to become a champion of life and sought to conquer even Death itself. When the various powers of the universe learned this, they sent the Watcher to appeal to Owen to do something to stop the Beyonder. At first Owen refused to do anything at all, until the Beyonder actually slew death. Realizing in a world where nothing dies there is no point to living Owen resumed his mantle of the Molecule Man and confronted the Beyonder explaining this to him. Realizing the error he made the Beyonder then restored Death from oblivion thus re-establishing the universal status quo.  When the Beyonder later decided to seek out solitude on a deserted island, Owen began to fear the worst, fearing that the Beyonder might obliterate them all.  When the Beyonder did become tired of the universe he was in and sought to destroy it, Owen tried to flee into a pocket dimension with Marsha but the Beyonder detected this and appeared before Owen before he could escape. In order to save her boyfriend's life, Marsha pretended to throw herself at the Beyonder telling him that she thought Owen was useless. This sudden rejection struck Owen with a deep depression and disgusted by Owen's lack of fortitude left him to live until he destroyed the entire universe.  However Owen quickly got over his dependency of his girlfriend but was happy to be reunited with her when she returned and explained her ruse. Owen then decided to put a stop to the Beyonder once and for all. By this point the Beyonder was attempting one last chance at understanding desire by trying to transform himself into a human form. Owen and Marsha then gathered the Fantastic Four, Avengers, X-Men, Alpha Flight, the Silver Surfer, the Thing, the Hulk, Powerman, and Iron Fist. While the heroes distracted the Beyonder the Molecule Man attacked him direct and the two were locked in combat. The powerful energies the two wielded in battle caused massive damage to the Rocky Mountains threatening to destroy the Earth. When the Beyonder attempted one final time to become human -- but with all of his massive power -- he used a machine that recreated him as a human baby. Unable to prevent this Owen was forced to use his powers to slay the infant Beyonder and send all his massive energies back to the universe it originated from.  However with the danger of the Beyonder seemingly gone, the Earth was still in death throes due to the damage sustained by the battle. The Molecule Man agreed to assist the Avengers in trying to repair the damage. This was no easy task and required the Molecule Man to combine his powers with the Silver Surfer repaired the damage. Knowing the heroes would try to incarcerate him over fear of his powers, Owen then pretended that by pushing his powers the limit the had burned them out, granting Owen some semblance of peace for a time. 
Secret Wars III
Owen and Marsha soon moved to New York City where they slipped back into a life of anonymity. This was all shattered when Dr. Doom appeared one day and savagely attacked the Molecule Man and leaving him dead. Doom then sought out the Fantastic Four to aid them on their quest into the Negative Zone to assist in their quest to learn the truth behind the Beyonders.  Owen was taken to a nearby hospital but left soon after he regained consciousness and used his powers to help himself. Picked up by Marsha, the pair decided to find out what Doom was after and using his powers to follow them. The trail led to the universe where Owen had previously transferred the Beyonder's energy into and found the Fantastic Four and Doom as well as the powerful cosmic beings known as the Shaper of Worlds and Kubik. There Owen and Marsha learned that Doom was attempting to regain his full memories lost during the first Secret Wars. The Shaper and Kubik also revealed another startling secret: that the Beyonders dimension was responsible for the energies that powered the various Cosmic Cubes that were created in their home dimension. Explaining that they were both Cosmic Cubes who gained sentience, the Shaper and Kubik went on to tell Owen that the accident that gave him his powers and awoken the Beyonder circumvented the entire process of creating a pure Cube and as a result both Owen and the Beyonder were incomplete components of a Cosmic Cube. Coming to realize that in order to be whole they would have to merge and become a Cosmic Cube, Owen and the Beyonder made peace and after saying goodbye to Marsha, Owen merged with the Beyonder and the two were transformed into a massive Cosmic Cube which was left in the null void of the Beyonder's realm to realize it's full potential.Fantastic Four #319. The Shaper of Worlds and Kubik were revealed as sentient Cosmic Cubes in Captain America Annual #7. In Fantastic Four #260Dr. Doom was seemingly killed in a battle with Terrax. However Fantastic Four #288 revealed that he actually used an old Ovoid mind transfer technique (learned in Fantastic Four #10) to transfer his mind into the body of Norman McArthur. In that same issue he broke into the Latverian embassy to get the supplies needed to cast a spell to summon the power to restore his original body. This turned out to be the Beyonder. The Fantastic Four's leader Mr. Fantastic then realized that the Doom they fought in the Secret Wars was from this point in the future and convinced the Beyonder to restore Doom's body, erase his memories of events and send him into the past to partake in the Secret Wars. It was this point in Doom's history that he participated in the events of Marvel Super Heroes Secret Wars #1 through 12. At the conclusion Doom was brought back just moments to his being sent back in time circa Fantastic Four #288 with no memory of his immediate past prior to the Secret Wars. Per Fantastic Four #319 Doom learned second hand accounts from McArthur and his family.</ref>
However this union between the Beyonder and Owen proved short lived when the Cosmic Cube evolved into a female form known as Kosmos.  Owen himself was ejected from the Cosmic Cube, stripped of his powers and returned to Earth. There he returned to his former apartment in Colorado where he thought over what to do for weeks. Fate brought Marsha briefly back into his life when she came to clean out the apartment and the two were reunited. However they were soon attacked by Owen's former partner, Klaw, who was employed by AIM to capture Owen in the hopes of learning the secrets of the powers he used to harness. During the course of the battle Marsha was surprised to find that she had access to powers she little fathomed she had. When Klaw was gaining the upper hand in combat, Owen revealed that he endowed some of his former power into her prior to merging with the Cosmic Cube. Marsha quickly relinquished this power back to Owen and he was reborn as the Molecule Man once again -- all be it with all his original limitations. When Owen destroyed the device that forced Klaw to work for AIM, he defeated them and then left, not caring about the job he was forced to do. In the aftermath of the battle Marsha confessed that she was not ready to get back into a relationship with Owen, especially in light their recent battle. Heartbroken, Owen left to give Marsha time to think. 
Fall From Grace
The Molecule Man entered a life of solitude in the Colorado Rockies where he constructed a home and a shrine to Marsha. It was during this time that Owen was manipulated by the Puppet Master to rescue his step-daughter Alicia Masters from Aron the Rogue Watcher when the Fantastic Four failed to rescue her.  Unaware that he was under the thrall of the Puppet Master, Owen raced to the arctic where he battled Aron. However the Watcher proved too powerful and Owen was defeated. When he awoke the Fantastic Four and Alicia were free and Aron defeated. Undetected, Owen wondered what compelled him to travel there and battle Aron, and silently fled the scene.  Owen eventually returned to his apartment and fell into a depression over losing Marsha. He eventually gave into his sorrow and let his evil persona resume control once again. With the so-called "real" Molecule Man back under control, he sought revenge against the being he blamed for losing Marsha: the Beyonder. Using his vast, and apparently once more limitless, power he pulled the Beyonder persona out of the body of Kosmos putting her in a death-like state. The two battled across time, space and dimensions, until Kubik caught up with them and forced them to see their battle threatened to destroy the universe. With Kosmo's life at stake as well, Kubik convinced Owen to come to terms with his grief. Seeing how wrong he was to lash out at others and not wishing to repeat the same mistakes as he did earlier in his career, Owen returned to normal and restored Kosmos as well. Owen then found a new found resolve and vowed to move onto a new chapter in his life -- even if it was just one step at a time. 
However Owen's mental state started to decay once again, and reverting back to his evil persona once more, Owen sought out the help of gamma powered psychiatrist Doc Samson to help him with his troubles. In kidnapping Samson, Owen drew the attention of She-Hulk who came to her friends aid. The battle helped Owen come to terms with losing Marsha all over again and reassert his good side once more. He thanked both Samson and She-Hulk and left the scene of the battle.  Owen later attended the wedding of Titania and Absorbing Man where he briefly ran into Marsha once again. When Marsha tried to strike up conversation with him, Owen angrily rejected her for dumping him.  Many months later, Owen was among a number of Fantastic Four foes that were gathered by the Puppet Master and the Mad Thinker. The Puppet Master suggested they pool their resources to destroy their foes, but unwilling to work together the collected villains then left the meeting, unaware that they left DNA samples behind as part of a complex plot by the Thinker.  These DNA samples ended up in the hands of the Fantastic Four who were manipulated by the Thinker into capturing all their old foes and imprisoning them in a new Vault prison in the Negative Zone. The Molecule Man was one of the many foes who were captured and imprisoned here.  Eventually Owen was transferred to the Raft prison off the coast of New York City. Shortly after this the supervillain known as Electro was hired to stage a prison break of the Raft. Despite the efforts of a group of heroes who would later form the New Avengers, Owen and many other prisoners managed to escape incarceration. 
With his mental state deteriorating again, the Molecule Man returned to Dinosaur, Colorado, his home town. There he sought to live in anonymity, using his powers to control the locals as well as disintegrate anyone who came in from out of town. His mind fractured, Owen created constructs based on the Enchantress, the Beyonder, and the demons Mephisto and Dormammu to act as his "advisers". He operated there for many months undetected until the disappearance of the daughter of a US Senator prompted Norman Osborn to send his so-called Dark Avengersto investigate. When they arrived with a HAMMER battalion, the group of heroes were easily defeated by Owen who took the Avengers and Osborn prisoner.  Using their own memories, Owen judged the Dark Avengers to determine if they were worthy of continued existence, however the group of "reformed" criminals proved to have qualities that Owen found unredeeming and was prepared to destroy them. He was forced to pause when Osborn's second in command, Victoria Hand, attempted to surrender on behalf of the United States government in order to avoid the Molecule Man causing more damage.  However while Owen was distracted the Avenger known as the Sentry was able to reform his body and attack. Learning how to manipulate his powers in the same way as the Molecule Man, the Sentry then used them to seemingly slay Owen, ending his threat. 
Time Runs Out
Owen's body was reformed and imprisoned by Dr. Doom who intended to use him to find out who was truly behind the Incursions and to stop them. 
Molecular Manipulation: The Molecule Man possesses the ability to mentally control, transform, and manipulate the molecules of all matter and energy. Owen Reece gained his extraordinary abilities by mutation through exposure to radiation from an experimental particle generator, which (as later revealed) also opened a "pinhole" into the dimension of the Beyonders, irradiating him with the energy that infuses a Cosmic Cube. Through concentration, he projects a psionic-manipulative energy, the precise nature of which is unknown, that alters the arrangement of molecules according to any visualized pattern. He can animate inanimate materials by causing constant mass movement of molecules: for example, he can make a brick building walk. He can rearrange molecules so radically, he can use his power to reconfigure all forms of matter and them into different substances and forms (such as, for example, turning air into glass), and can change matter into energy and back again. He can create force fields and energy blasts, and also open up wormholes through hyperspace and traverse them, thus travelling faster than light. The maximum area he can affect at a single time is not yet known. In the past, however, he has enclosed the entire island of Manhattan in a plexiglass barrier, lifted a 150 billion ton mountain under his own power alone, converted a two-square mile parcel of land into an ornate palace, and, with assistance from the Silver Surfer, affected the entire planet Earth. Once he effects a change in the arrangement of molecules in a quantity of matter, it remains in its new configuration until he consciously changes it back. Even if rendered unconscious, the transformed substances remain. The Molecule Man can even affect the molecules of matter with mystical properties (such as Thor's hammer), matter fashioned by vast cosmic power (the Silver Surfer's surfboard), and matter composed of the most impervious materials devised by man (Captain America's steel alloy-vibranium shield). The process of molecular manipulation does not cause the Molecule Man any more exertion than performing simple arithmetic. Although the energies that gave Owen Reece his powers came from the same power source as the Cosmic Cubes, Owen Reece generally does not use this capability to the same extent as "true" Cosmic Cubes do, limiting himself to manipulation of "mere" matter and energy. Regardless he has been able to effortlessly recreate an entire galaxy even in his regular state, and on a later occasion unleashed his 'darkest aspect', which possessed sufficient might to fight, and overpower, the Beyonder in a more than 3-dimensional battle, which in turn was claimed by Kubik to be far less than his full potential.
The Molecule Man is a physically below average human being with no athletic abilities or fighting skills.
Originally, the Molecule Man subconsciously imposed mental blocks on himself to prevent his using his powers to their full potential. Hence, he believed his powers were ineffective on organic molecules. Although he overcame this mental block in the past, for unknown reasons he is again unable to control organic molecules. The Molecule Man formerly had a psychological dependency on using a steel rod ("wand") to focus his powers but he subsequently learned how to direct his powers without it. Also, in the past, the Molecule Man has had trouble understanding complex technology, circuitry, and machinery.
Molecule Man's Wand: The Molecule Man used to employ an ordinary steel rod as a prop to help him focus his powers. He has since learned to direct his powers without the use of a medium. His "son", for as yet unknown reasons, was able to use the rod to affect the molecules of organic matter, a power the Molecule Man himself did not possess for a time.