The only one who was ever forceful was Yahwi. Yes he had a little bit of a character development but it's clear as day it was too late, Jooin explained perfectly why in the last two chapters. They can't become a couple because Jooin's love turned into just compassion and even Yahwi decided to give up.
Cain is not weird but Yahwi stans just loved to badmouth him 24/7 when he was the only one who made Jooin laugh and supported him throughout the entire story. It was Jooin's wish for Cain to become a human in his next life, so here we are now. They're reunited as humans and they both have feelings for each other. It's best to let go now buddie..
I sincerely hope it's Yahwi and Jooin at the end though I see a lot of comments saying Jooin effectively ended any hopes of a relationship in the last chapter...But come on, Cain used to be Jooin's pet in his past life and that's just weird!!! We saw the most development from Yahwi and Jooin's relationship, including Jooin's feelings. Cain was the weird, convenient stranger who followed him to Korea and kind of forced himself into his life. Jooin wasn't in love with Cain - he was a shoulder to cry on. I personally would consider it a copout if they were endgame, probably because I wasn't as invested in their relationship...My heart broke for Yahwi in this chapter (Cain already found his master in his current life, that should be enough!!!) Honestly, I get that people are tired of the toxic seme trope, but I do wish the author had just introduced a normal guy who was not reincarnated and organically grew to love Jooin if she wanted us to see the second guy as a serious option.
Also, if the author decides NOT to follow yaoi story tropes and have Jooin end up with the second guy who came later, then I hope Yahwi finds someone else to love him.