Darwin's Game (Manga)
Do you remember Sword Art Online? That anime that has an incredibly interesting setting, but managed to ruin it completely by focusing on harem establishment and creating waifus for lonely men in their fifties instead of the bloody battles that we actually came for?
Well, Darwin's game is what SAO should've been. People killing each other in a death game. However, unlike SAO, in Darwins game they fight in reality with superpowers gained from a forced evolution of their DNA and assault rifles.