Kronos is a General of Overlord's army. He is the Demon of Lightning and Ice. He is also the Father of Zeus and Reginald Neptune. He is also a spirit in the Darkworld.
Kronos ate his children, Zeus, and Reginald Neptune to prevent his duties to the Overlord and fail him. Then his sons broke free and attacked him as the other ancients fought the Overlord's Generals, and Kronos, with the other Generals, were banished to different dungeons in the various temples of the Ancients.