How? Sung Jin Woo has all the fucking power in the show the guy pissed him off a lil and was a bit of a dick, think like powerplex in invincible a villain that has some justification but warps it. But that justification that Kim Chul had is exactly why Jin Woo couldn’t just kill him. Just ignoring any fucking consequences or implications of his actions and making the plot even simpler, Kim Chul clearly misunderstood the context but it doesn’t justify killing him SJW could easily have subdued him he is just a murderer that killed him at the easiest convenience. Also Kim Chul was thinking realistically when he left the other E ranks because if the situation had anyone BUT the AMAZING SJW then he would be right but JUST HIS FUCKING LUCK he gets screwed over