he doesn't give any warning and when it turns out to have a hypnotizing effect, he takes advantage of it.

Instead of just telling Iruka that he wants him to relax more during sex or to be more submissive or honest, or you know, just letting Iruka be what he was comfortable with, he roofies him and rapes him, using the hypnotization to make him more docile and follow his instructions, despite the fact that it was clearly hurting Iruka.

And then in the end Iruka forgave him, saying it was his own fault for trusting Kakashi.

If it were me, I'd never trust Kakashi again, especially after that ending where he brings another pill home, and in the second half there are more pills. Even when Kakashi ends up taking the pills Iruka still ends up giving into him. At least it seemed consensual then. Maybe at least after that ending Iruka will get top??

If Kakashi can't be with Iruka without wanting him to be exactly as he thinks he should be for Kakashi's sake, he needs to hit the curb.

I also found Asuma and Kurenai's involvement to be disgusting. They would never assist in rape.