Yaritsukai to, Kuroneko.

Kagari Shuuya found himself inside a white room where he was shown a futuristic interface to reincarnate in another world. He was given choices of race and 4 extra skills. Among the myriad of races up for selection, he chose to be a half-vampire, a race similar to human in appearance, but has most of the advantages of a vampire with the sole weakness of Light attribute magic. But he exploited that weakness by choosing an extra skill that allows him to use Light magic. That combination somehow produced a brand new species that unites light and darkness, Seivalt. The other 3 extra skills were Language Comprehension, Chain Projection, and Growth Modifier. With such cheaty line-ups he was transported to another world, but the destination was a very severe place that even with his cheats it’s not easy to survive, the vast underground world. He could beat most enemies, but there’s no way out, there’s no people, a world of loneliness. After few months surviving in that dark world, he braved himself to venture even further. There he encountered a white giant winged beast, an apostle, which instantly made holes in his body and consuming flesh. As his wounds were healing, he kept running until he reached an altar that enshrined a black tiger statue. The apostle caught up to him and 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.Source: Manga Updates