Wutong of the Abyss

Honkai: Wutong of the Abyss, also known as Honkai: I'll Change Everyone's Ending [Honkai, dual personalities, protagonist gradually grows stronger] The beginning is original; the story turns to the Previous Era midway through. Elysia is the heroine. A little angst, some sweetness, a slow burn, and a slice-of-life focus. After Wutong sacrificed himself to save his own world, Elysia happened to encounter a Wutong from another world bubble. But Honkai was still carrying out some kind of plan, and the new world was merging. Once again, they faced Honkai. This time, I don't want to lose anyone!