At least dealing with Lucifer is familiar now. He would rather be coping with his drama over getting in the midst of someone else's. Istredd isn't concerned with the meeting though, it appears that people are talking amongst themselves and signing up for training, as he had hoped. Perhaps it was a success after all.

He knows he is intentionally avoiding the question now which means Istredd is going to let it go. He doubts this is the last time they will discuss it, but it doesn't have to be now.

It was very long and ill-advised, he revealed personal memories from Rhy and whoever the woman was without asking. But it also said that Rhy was stuck in the Horizon. It appears to be a rare situation though, and we know he has a unique relationship with the Singularity. Dean likely doesn't have that.

It is a puzzle to work out for certain, but Istredd is willing to work with theories to keep them both safe from the Mark's inevitable murder spree. He would reach out to Geralt to warn him, but that is really not their type of connection. Little does he know how aware of it he is. Is giving it to someone else the only option to get rid of it? The rules could be different here.