
This manhwa awakened the okabe rintarou, akemi homura and Kim dokja PTSD within me. I'm a sucker for regression plot but every single one of them never fails to make me crying ugly

Sure. Actually 2 of the characters I mentioned is from anime/visual novel.
Okabe rintarou is from anime called Steins Gate. Here the ML tries hard to save his precious childhood friend and the FL.
The concept here is time machine/time leap/different world line (kinda like parallel world settings). The story starts off slow burn like your typical slice of life but when you reached ep 12, everything hits like a truck. If you are interested there's a watch order:
Steins Gate(2011)(ep 1-22)
Steins Gate 0(2018)
Steins Gate(2011)(ep 23-24)
The second one is Akemi Homura. She is from the anime called Madoka Magical. At first this anime may seems like silly Magical girl anime but when ep 3 came around, just prepare your heart because lot of angst coming. The concept here is time rewinding where she keeps on rewinding time to save her friend Madoka Kaname. It is implied that Homura had romantic feelings for Madoka basically making this story a bit of a GL(Yuri).
The continuation for this anime is Madoka Magical Rebellion.
The third one is already pretty well known, he is Kim Dokja, the MC from Mahwa Omniscience Reader Viewpoint(ORV). The manhwa is pretty good, as it is set with game-like system and post-apocalyptic settings. The manhwa cuts a lot of things, so I recommend reading the novel instead.
As for the BL manhwa category, I've read a few that I considered quite good.
https://www.mangago.zone/read-
manga/again_1/
https://www.mangago.zone/read-manga/success_oriented_guide/

Contrary to what other people think, I actually like MC personality. Yes he's an airhead, but precisely because of that he had such strong unbreakable will to pursue the ML and guess what, he won in the end. The art is cute, the smut arent that bad as people made it seem to be. This story is a comedy with some doses of real life reality sprinkle here and there and I honestly like the legal aspects portrayed in this manhwa.
Heechan really had a well developed character development, from being uncaring about Taekin situations to one of his closest colleagues when Taekin returned to his body. As of right now, Heechan is still asexual, but with Minjae manipulation here and there they both will eventually fall in love with each other.
But with that said, class pres brother really need to be put to death. What a gawddamn disgsuting sexual predator