3x3 Eyes

Having an archaeologist dad go missing in Tibet should be the biggest problem in Yakumo Fujii's life — that is, until a strange girl named Pai shows up at his door, and within about twenty minutes of meeting her, he's dead. Sort of. Pai is the last surviving member of the Sanjiyan Unkara — an ancient race of three-eyed supernatural beings — and to save Yakumo's life after things go very wrong very fast, she absorbs his soul. Now he's her 'Wu,' an immortal servant who can regenerate from basically anything but can't actually die while Pai lives. The catch is he didn't exactly volunteer for this. Together they're hunting a mythical artifact called the Statue of Humanity that could make Pai fully human, which she desperately wants. The other catch is that Pai has a split personality — one side is a sweet, childlike girl who has no memory of her other self, and the other is an ancient, powerful demon who absolutely does not have time for your feelings. This is a 4-episode OVA from 1991, so it moves fast and leans hard into the darker side of its mythology. If you liked the early arcs of Bleach or the grim supernatural tone of Blood Reign: Curse of the Yoma, there's a lot here that'll feel familiar. The horror and gore are real, but there's genuine emotional weight underneath it all.