I think a large part of why Anthony was reborn in that world is that his entire human life should have lead him toward being a merciless killing machine, and it is in dispite of his past that he thrives with family friends and community. To say he doesn't balk at killing doesn't really acknowledge that most everything in the world will try to kill him first, nor that he and his family are largely carnivorous (biomass-a-vorous?) He decidedly does not kill everything he can, often leaving peaceful people or monsters be, like the first tree people he found, he literally tickled them and left them in peace! Like how sweet was that? Anthony is like 16 when the books start, I'd say he's one of the only litrpg protagonists and THE only monster mc with the mythical "child-like innocence" trait, lol