Destiny Unchain Online: Kyuuketsuki Shoujo to Natte, Yagate 'Aka no Maou' to Yobareru You ni Narimashita

Kou Mitsuki is a gamer with god-tier skills, known online as Crim the Headhunter. Right when he starts testing his father’s latest game, Destiny Unchain Online, and the new device developed for it, the bug-ridden system transforms him in into a vampire girl! Everything changes for Kou as he meets new friends and they take on the game… The ultimate gamer adventure awaits! *Source: K Manga*