He had realized that 7 years before, i guess after he met Chansol again as deskmate, he was planning to make Chansol fall in love with him slowly but after Chansol disappearance he became obsessed with August in hope that Chansol will come for the information he had
But wasn't his thoughts before about Chansol being his toy. Didn't he really realize when Chansol was angry a few chapters ago? Didn't make Chansols worrds him realize in the end?
ahhh this was so sudden .He realized that sooner than I expected