Responses
I think it happened coz he always forced yorong to deal with his negative emotions which caused him to act up so much so when jin stopped doing this due to the mc's feelings for yorong , which is why yorong calmed down, jin had no idea how to deal with the emotions and therefore didnt know how do release them healthily. Thats my theory anyway. ╮(￣▽￣)╭
Honestly this made no sense Turing jin into a bad guy just so we can be happy about Yorong like they should of merge and share the uke