Greninja’s Protean

Greninja

Has anyone else noticed Greninja’s Hidden Ability Protean? View Greninja’s Pokedex Here

Protean basically allows Greninja to change it’s typing before it attacks to that same typing. This not only means Greninja gains STAB on all it’s moves but you can essentially change it’s typing every turn making it very hard for your opponent to get a decent hit off on it. It starts off normally as a Water/Dark type but let’s say it uses Aerial Ace (for example) it becomes a pure Flying type making that nasty ground move that was about to hurt you badly completely useless!

It’s moveset is somewhat diverse in-terms of typing allowing for pure Psychic, Fighting, Dark, Normal,¬†Ghosts, Ground, Ice, Rock, and even Grass. Questions is what kind of moveset would offer it the best type of coverage against the most common types of foes? Any ideas?