It's going to need an evil to dig vampireness out of his torching template. He doesn't have any on hand, and it would feel vaguely weird to ask Stella to give him one, since she's so unsure about this in the first place. So he sets himself on fire.

It takes him a few tries, about thirty stars' worth, but he manages an evil in the end. He uses an existing star to declaw the new ones - ever since the Jokers were let in on the secret, some of them have taken to carrying all their coins declawed, even the hexes - and then uses one of those to declaw the evil.

Then he designs the wish.

He wants to stop being a vampire. He can get rid of his also-permanent air filter while he's at it. He should also be immune to vampire venom, because it seems not-impossible that he might want to get bit at some point; he'll take the Joker's version of immunity, which is linked to his regeneration and therefore hurts a lot, that's always fun.

He can go either way on the brainspace available to vampires, but the depth of emotional processing - he's keeping that, in some other form that won't lead to him still having a mate bond by accident. He bets his power will help sort that one out. He wonders what Lazarus would say about its attitude to his mate bond now. They are probably not snuggling so happily anymore.

Is that it? He thinks that's it.