The bad guy/ friend's father was an actual bad guy, so I understood that ml's family (probably with backing from the palace) exexuted the friend's whole clan to put an end to the corruption. It probably wasn't uncommon to kill the whole household if the family head's a criminal, and ml knew about the plan beforehand and saved his friend. Understandably the friend wants to take revenge on ml for killing his whole family (his wife included apparently) and not helping him in another way. So I'd say he's not even that much of a bad guy
Ahhh that makes sense. Thank you so much, confused potato!
Okay so idk if I forgot or I'm stoopid but I didn't get why the bad guy wanted to kill ml? What was their story I'm confused. Ml killed his family?