Kronos had gone to the planet of Titan per the Eternals' agreement that some would go with Mentor and the rest with Zuras.
Kronos was working in his laboratory in the Earth Eternals' city of Titanos on an experiment with cosmic energy when he accidentally caused an explosion that destroyed Titanos and Kronos' physical body. However his mind survived and became one with the universe and time.
Kronos possesses a level of intelligence that ranks far above superhuman, and well as telepathy, and cosmic awareness. He can evidently exert control over the souls of deceased mortals, even to the extent of using them to animate artificial bodies, which he can create from inanimate matter. Kronos has also become one of the embodiments of time, and as such can exert an unknown degree of control over its flow, which he does in very subtle ways when required.