So... looking over the Messiah, if they made Preach Unto the Choir a favored Blemish, and then used their temporary warp points from their penitents to boost their warp above their character level, they could have an auto-death effect for things several hit dice above their ECL... Doesn't that seem kind of broken? It's so much stronger than pretty much all the other options that it is a bit ludicrous.
I really love the flavor of the class, and the mechanics for Outcasts are definitely interesting. I plan on playing a Messiah in a gestalt game, but I won't be taking this Blemish, just due to the fact that it is either horribly overpowered or mostly useless, depending on whether you make it a favored one or not. It's really more of a problem with the spells themselves...