I'm not too fond of only being locked into one move with the protean ability, I also tried Wise Glasses but not enough damage, I also tried Expert belt and although Greninja's cover is great it's somewhat situational. Here's a physical set if you would like to know.
Greninja
Moves: Power up Punch, Substitute, Water Shuriken, Shadow Sneak
Nature: Jolly/Adamant
Take your pick the nature depends on the teams goal as well as considering that two of your attacks are priority.
Ability: Protean
252Atk 252Speed 6HP