what

To break the imprint

To boost his Guiding ability since what he was previously doing wasnt enough and since they were imprinted no other guide could help him guide his esper more. But the drugs could also cause him to lose his guiding ability or even die that's why kwon was super angry when he realized they told dowon about the drug.
Also to break the imprint is to imprint with someone else or one of them passes away. No drug can remove it

right…