That's the great thing about Greninja; it has no shortage of options. Protean is just such a cool and unique ability, so I'm curious to see how it will be used in the standard metagame. Offensively, it gives Greninja STAB on everything, essentially giving it a free Choice Specs boost to any moves that weren't already STAB. Support-wise, it can set up Spikes and then use Shadow Sneak or HP Ghost to change into a Ghost-type and spinblock its own hazards. Base 122 Spe is downright amazing as well, beating pretty much every unboosted Pokemon in the current OU besides Jolteon, as well as letting it outspeed every Scarf user with base 65 Spe and slower (Scizor, Gothitelle, and Tyranitar, for example).
By the way, that was supposed to be "escaping from counters" in my last post instead of "escaping from hazards," lol.