History is Written By the Victors

The titular adage is as true in Terafa as everywhere else. However, in Terafa it is also metaphysically true. This means two things:

Firstly, where there is a change to the pantheon, such as the death of a god, the rise of a new god, a promotion, demotion, or other change, that is very quickly reflected in the world - where a god rises, there will very quickly be temples and priesthoods springing up, cults, believers, and indeed heresies associated with that god. It is almost as if these things come into being whole-cloth. Conversely, when a god falls her temples will very quickly fall out of use, becoming decayed ruins, and either be abandoned or indeed swept away.

Secondly, however, any such changes are actually retroactive, both in that the legends surrounding the god will be edited to match the new reality (although such things are rarely done in a truly comprehensive manner - some vestiges of the old order almost always remain), but also in the history itself. Thus, if one were to cast a spell to travel back in time to the founding of the universe, one would find that the greater gods were Choriam, Li, Klos, The Thought, and The Twins (and there would be two suns, not one), and The Usurper would be confined to the Fastness of the Divine. That applies even though mythology (correctly) identifies that The Thought came into being following the Upheaval, and that Jolin was originally the greater god of the sun.

This of course means that there are effectively some break points beyond which time travel is effectively not possible - any time the pantheon changes, this closes off the past that has led to that point. Any attempt to time travel back beyond that point won't take you back to the way things were originally; it will take you back to a very similar parallel timeline where the pantheon matches the way things have always been. Or something - time travel just gets weird.