That would actually be interesting. Here are a few ideas of what they might say based on what they know about MC so far (remember, Jester, Ticket Taker, and Doctor don’t know much about MC yet)
Pierrot: I knew I would find my way to you eventually, my dear. There is only a screen separating us now, and I will find a way to cross it.
Harlequin: Oh, so you have been playing with us this entire time? Just wait until I get to play with you in person~
Ticket Taker: So that is how it was… how you always seemed to know everything. I believe I could grow rather fond of such a mechanism.
Jester: So you truly do live in another world. Your reality gives me power… and it will be quite entertaining once I finally arrive there.
Doctor: So this is where you were hiding, sweetie? Once I cross that screen, I would very much like to study the changes your body undergoes within your reality.