I agree with Garland and TheAbominatrix.

Dark Wave would've been good if it didn't use up an eighth of the Dark Knight's health. Since it does so, it sucks. And curative magic and being able to damage undead negates any other advantages the Dark Knight might have (which, for the record, are none whatsoever). So yes, the only reason I can possibly see to prefer the Dark Knight is his appearance, which is indeed genearlly cooler than that of the Paladin (at least in terms of sprites).

The Dark Knight *is* a cool concept, I have to admit. But he pales in comparison to the Paladin in terms of battle effectiveness. And the Mount Ordeals scene was cooler than the concept of the Dark Knight, anyway.