I was reborn as a Leviathan in Genshin Impact.

A long, long time ago there was a small black worm, a human reborn with a system in Teyvat.
This worm met people and grew and grew until it became truly massive.
A Leviathan.
And yet, as its lifespan seemed to stretch on and on, it realized its immortality.
And as its age stretched on and on into the thousands of years, it forgot many things.
The cooking of its mother, her face, her voice, now all it remembers is the concept of her, the vague warmth of her embrace.
It forgot what it's like to be a human, and its soul yearned to remember.
With its age reaching the third thousand, its system is deactivated, determining that its host has reached the apex of all life in Teyvat. Untouchable by even Celestia itself.
And yet, with a single catastrophic error, it deleted all of the skills, abilities, and spells with it.
Now all that the previously untouchable Patriarch has is its withering mind, its vague memory, and its colossal body.
With its subordinates- fellow Leviathans far older than it, unhappy with its rule, it left them behind to journey across Teyvat once more.
New friends shall be made, old allies reunited, and at the end of it all- Immortality will either be a curse- or a boon.
-x-x-x-
This is an AU of Genshin Impact, I will change things as I see fit. This includes making some characters weaker, others stronger, or even putting in my own characters.