Arifureta Shokugyou de Sekai Saikyou

Hajime Nagumo and his classmates are summoned to another world as heroes, but while the others receive impressive combat abilities, his transmutation skill seems almost useless. During an expedition into the Great Orcus Labyrinth, betrayal sends Hajime plunging into depths filled with monsters and leaves him with no one to depend on but himself. Survival forces him to remake both his body and his outlook. Deep underground he meets Yue, a vampire imprisoned for years, and the two begin searching for a way out. The weakest student in the group starts becoming someone the world can no longer dismiss.