Actually, Corsola has Hustle, the Marill family gets Huge Power, and Vulpix's line has flash fire. To be fair, Sandstream and Water Absorb are both exclusive to non-Hoenn dex Pokemon, but they are both variations of abilities already in the Hoenn dex (Drizzle/Drought and Volt Absorb). I'm sure there are a couple of others like that (Limber is the first to come to mind), so my question is a bit more complex - are there any abilities outside the Hoenn dex that aren't in any way related to ones already in it? For example, Ditto, Hitmonlee, and Persian all get Limber, and aren't anywhere in Hoenn, but Limber is basically Water Veil for Paralysis. On the other hand, Clefairy only has Cute Charm in Gen III, which is a fairly well-distributed ability, and gets the entirely unique Magic Guard in Gen IV.