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.