This is a theory but I have a feeling that the one DJ MD likes is Dong-gyun's friend because when they show the flash using MD's point of view it's always Dong-gyun and his friend, so he is probably sucking up to Dong-gyun to help set him up with his friend
Actually on the raws the real target is DG's friend
DEDUCTION TIME
SUSPECTS
Kyon:- he could not have done it because he is too in love with Lucaon and wants to stay by his side
Ryan:- has a sense of parenthood to Lucaon and would do anything to protect Lucaon so rule him out
Cecil:- if you realised Cecil is afraid of Ryan so she would not want to do anything to tick off Ryan
Karis:- even though Karis doesn't like Lucaon, he knows that Lucaon is a treasured friend of Sihan
Logan:- he is a wild card. Remember when he gave Kyon the ice- cream to eat with Lucaon, that could have had the VS solution in it HOWEVER it is not him else when Cecil came for the first time she would of saw that his core had already been corrupted in other words it can't be him
Christopher:- just recently you must who urged Kyon to make tea and drink it with Lucaon? Who was there with Kyon in the kitchen? And the same chapter a bottle of VS solution was on the ground with Sihan and Karis were having sex. After drinking that tea, when Cecil came suddenlt his core was corrupted
CHRISTOPHER IS GUILTY!!!!!!!
This entire flashback is being told with Alex deep in the tunnel XD