It took a but of searching but I found him in the genderbent dimension. His name is Darkhorse Knight, aka Prince Artemis.

Darkhorse: What did you bring me here for? I am kind of busy.

Luna: I have been dared to kiss you, even though we are the same pony...technically.

Darkhorse: Um... I don't know you like that. Sorry.

Luna: *kisses* Get out of here you jerk. *teleports Darkhorse back where he belongs*