Strictly speaking from a mechanical view, that character is going nowhere fast. Assuming he's a human, he'll be able to have whatever class he puts the most levels in be a favored class, and PrC's don't count towards xp penalties, but unless you work out a system for advancing each class sequentially (not counting the highest one, as a human), you're going to take serious hits in xps as you advance, making it harder and harder to gain levels, resulting in a bigger and bigger gap between you and other party members. What's more, although your character will have the hit points, saving bonuses, BABs, etc, don't count on getting too many special abilities. If you take that PrC, and evenly advance all your classes, you won't get further than fourth level in any of them by the time your character levels hit 20. You won't be raging that long or having any DR, wont get too many bonus feats, won't be able to sneak attack for much as all, and don't count on casting a divine spell greater than level 2 (though Im not sure what the Warpriest adds, so this might up enough to get you up to level 3 divine spells....yay). Ultimately, it is kind of obnoxious, but in my view, you're going to pay the biggest price for this.