Are y'all fr?!!

That’s true.. it’s just hard to trust him after he dismembered his crush, has violent kinks in sex, and beats people half to death that press the wrong button

Well, he is mentally unstable. He's actually VERY naive and just get easily carried away by anyone he trusts, because he can't actually tell if someone is genuine or not, like his uncle, he blindly believe his words, unlike his brother.

The thing is Heonjae is someone who is capable of doing bad things, just because those behaviours haven't been directed towards children and women doesn't mean he should be trusted to be alongside them. I'm not saying that he should never be allowed to exist among other people, but this has come prematurely, especially when the last act that myeongil and the readers had seen of him is a murder attempt and using a non-consenting individual to cause self harm. I'm not sure what other reaction are we supposed to have over this situation, are we supposed to go uwu cause he's with vulnerable kids and grandma now?

Well said.

He is, when he gets fooled by those he trusts. Which right now he only trusts MC, no one else besides him. If you read properly you'll see that he only did that because his teacher was using him and explored to his limits. Then his uncle, one he thought that was someone good, fooled him into doing something criminal, because he actually hates both brothers. Now he himself said he only wants to live a better life and not as a criminal, he wants to live peacefully with MC.

Heonjae has no control over his violent tendencies. He beat up a person with a hammer for talking about what he did to the teacher. Even if his teacher was financially abusing him and cheating him cutting his legs is extreme violence that normal people cannot and will not resort to. He is not someone who can be peaceful just by deciding.