Did this guy really just see Red's bed and immediately assume he's going to screw his sister on it?
Yes, he's projecting HARD on Redion! Everything he says about him, everything he thinks about him, is stuff he himself is planning in a way or something he realizes about himself.
The most useless of them all was him after all. All he brought to the party was firepower, something Ruti has more than enough already and Musclebro was there too and was able to actually shield other people better, since being only 1 person and not being able to fight all fronts at the same time is the only real problem with Ruti. Hell, Redion shielded him all the time so he could do his thing!
Redion was also the mouthpiece of the party, with a charisma stat not in the negatives, which also made the "Sage" completely redundant. Not to mention that Redion was easily the most sociable of them all, so any conflict in the party or with other parties was immediately solved. Meanwhile Ares' only social skill is brownnosing...