I'm designing an encounter for a skilled group of level 1s. What I'm trying to do is set up a villain that the party would have to fight later; thus, this encounter is supposed to be a forced loss. (Think the first Bowser battle from the original Paper Mario.)
My question is, how should I create this villain at so that he looks beatable but, even with the players' skill, he is not and a wipe would be guaranteed? Thanks!
EDIT: There are five players in the group: a paladin, a monk, a barbarian, a cleric, and a ranger.