It hits differently when you have read the light novel and remember the story until now and know that most of his shadows have been on the other end of his rage so when they shake the memories come back...
Your right about him beating a guy weaker than him but it really is not a convenient perfect time because he is already too late his friend is already beaten up and losing blood
Jinwoo is so angry even his shadow soldiers tremble! I've been waiting for him to beat this guy up for a long time. This is going to be so satisfying!!
Ya fucked up, fucked up you now have. You know it's head when every single one of his shadow soldiers trembles due to his rage. There's gonna be a LOT of property damage....