Cronus
Cronus is the Greek titan of time. He is the son of Gaea and Uranus, and the father of many of the gods in the Greek pantheon, notably Zeus, Hades, and Poseidon. He is best known for being such an awful father that he got himself locked in Tartarus for the rest of eternity. The myth states that Cronus once received a prophesy saying his kids would overthrow him, so he did the only rational thing any father would do and fucking ate them. Shockingly, his kids resented him a bit for that, and decided to overthrow him and lock him in hell forever as punishment (a Greek myth about a prophecy being self-fulfilled? Say it ain't so!).
Given that he is effectively the embodiment of time, his power is absolutely mind-boggling. It would take multiple conventional gods to pose a threat to him in any meaningful way. It took the three most powerful gods in the Greek pantheon to overthrow him, and it wasn't exactly a cakewalk.
Cronus is usually depicted as chaotic evil, and his followers should be as well. Given his mastery over the temporal, most of his followers would likely be mages or sorcerers.
Like many other figures of Greek myth, Cronus has left an impact on modern language. Chrono is used to refer to things related to time. It is typically found in compound words and rarely seen standalone outside of video game titles.