Wannabe Vampire and transferal potion.

[Pauliboy1031]

Something happened during a combat in my latest game.
So I'm gonna call players
P1 (Player in combat), P2 (Other dude), P3 (myself).

P1 is a cleric, he draws King Tut, P3 has CP of 3. So, taking advantage of the undead property of king tut, he adds Mr. Bones (and then he uses Polymorph Potion on king tut.

P2 Adds Leperchaun with Wandering Monster.
P1 plays Magic Misile. giving a P3 - 8/ Monsters 6

P3 Adds Wannabe Vampire with Wandering Monster.
P1 uses the boogah boogah property of Cleric Vs Wannabe Vampire.
After everything was resolved P3 Uses Transferal position to fight himself the 2 remaining monster.

The dilema was: According to the P1 & P2, the Wannabe Vampire has to comeback, because P3 is not a Cleric. P3 says, Vampire already left the combat and he cannot come back.
Who was right?

Edit: At the end, Vampire didn't return, but other players were not too happy about it.

[Brf]

There is nothing in the rules for returning a removed monster to the combat. Once it is removed, it is gone.