He acts like he cares so much but in the beginning he’s like “oh I’ll just rape him ...

I think it's the opposite tho, he acts and makes himself believe that he's just keeping him alive coz he's horny for him and waiting to jump him to avoid realizing that his feelings are actually genuine care (which is more troublesome for his mission), with the horny mindset there's an end- once he sleeps with him, then he can proceed with the mission, but with realizing that he cares for him, he'll just be plagued to choose between him or the success of his goal- I think this is implied on his monologue in the last chapter.

I guess