20,000 years ago, you were hailed as the most powerful being in history. The God of Gods. But you were so powerful that it bore you, so you decided to leave the Earth with your last words being "i shall return in a millennia." to your followers.

Somehow, the humans misinterpreted your words as reincarnation, so they built an academy to nourish the new generation in the belief that you will need a vessel. But yeah, that didn't happen.

20,000 years have passed on Earth. And it suddenly came to you your own words, so you had no choice but to descend once again.