how glory and action and bloody i can go in my game . i can make a glory kill system seen in doom and doom eternal or i cant also i can use  my own engine ?

i dont know

Probably it would be rated MA then but just dont

It also says no gore

Yeah that idea may not go over well due to rule 3:

3. No NSFW or obscene content. This includes text, images, or links featuring nudity, sex, hard violence, or other graphically disturbing content.