A Warhammer 40,000 space marine is not just your usual sci-fi super soldier. They are hulking behemoths, 10 feet tall (and about 10 feet wide too). They don’t move like people, they move like freight trains. They have the physical bearing of an industrial freezer unit and the emotional intelligence of a crocodile. They do not retreat and they do not surrender, and their 9-to-5 is fighting the worst things you can possibly imagine over and over in a completely futile forever-war.
Then just throw in the good old human/elves/ork/bad human rhetoric and add space or dark to everything.
Gotta add that the orcs in 40k are mushrooms!
Nah they’re just a fun guy.