Norowareta sekai

this is the story of a boy that was abandon for unknown reasons forced to live in a orphanage his soul harden he turned to a life of alien slaying. After they had invaded earth they spread their parasites across the world. It infected everyone some people would die because they were incompatible, if the parasite host was 50% compatible or more. They would either be a demon(basic power), chimera-(jack of all trait), god-(unreal powers) or a awakened host-(human with power that can do defense or offense). Those whose mind was taken over became mindless.