Yaritsukai to, Kuroneko.

Kagari Shuuya found himself inside a white room where he was shown a futuristic interface to reincarnate in another world. Among the myriad of races up for selection, he chose to be a half-vampire. After few months surviving in that dark world, he encountered a white giant winged beast, an apostle. They commenced a life and death battle. Shuuya’s body was torn apart and his flesh littered the area, but then his vampiric blood went berserk and the predator changed. The apostle got her blood and soul drained and Shuuya lost his consciousness. In the silence, Shuuya’s flesh and blood gathered and formed into a small cute black cat. In the distant past, it was called a Divine Beast, now it’s a cute cat that will accompany Shuuya in his adventures.