You'll love it when he scams the goddess into giving him semi-mythic grade class, then get another semi mythic grade class from Belial

1) the MC is not the returnee but someone that discovers it and, to guarantee his survival, sticks to him; 2) the MC is weak, at least until now, albeit having a skill that allows him to see stats and that certainly will be a cheat in the future (Mind's eye) ; 3) he deals with things with his wits and mostly using other people. He is not a genius, though, he knows it and the novel shows it to us too. (OBS: he is an alchemist, but we really don't see this being explored as the variety of his moves are too little, and recently with a 4y time skip in chap 295 and the author simply forgot to show us his stats, lol, frustrating, kind of like he is saying "his strength is not important, have no hope until the end where he will get some cheats (something) ".)

Not really developed, there's more development in his bromance that in his romance. There's no chemistry with the dragon or with the priest, the first one can't be called a harem member at all and appears just to give the MC a new job/class, and the second kind of disappears to the point you think she's there just to complement the squad (the first doesn't even like him, the second likes but not that much, and he doesn't have feelings for them). Yuno, the japanese that can see the future and the alternative world where the returnee comes from, at least seem to really like him, but he doesn't, and she's there more as an utility than a romantic interest. Cha Hee-ra (or something like that), the guild master of the Red Mercenaries, is genuinely interested in him (at least sexually, lol, mostly cause of his unique status of attracting crazy women) but he, as always, doesn't seem to like her. Lee Jihye, later acquired the class commander, helps him with his schemes and is what the system calls soulmate but there's no relevant romantic development (seems to like him a little, and he seems to like that she is useful, lol).

Lastly Jung Hayan, the genius (and ret*rded) future archmage and the only one the MC seems to like, is an obsessed crazy yandere that falls for him in the tutorial dungeon. It's almost like the other women exist just so she becomes crazier and do more shit. She is the cause I think the MC is tr*sh: she killed a woman (Park something) in the tutorial just cause of a handshake, and we see the MC struggle to fake believing her lie while watching the girl die (to preserve his life, in this situation I understand), and she does/tries to do similar things from time to time, but the MC still seems to have fallen for her and that makes me want to puke.

they tend to be pretty psycho so its not just regurgitated tropes