If you're worried about special walls with Tapu Koko you could simply run Taunt or Volt Switch/U-Turn and wear them down like that. Nature's Madness and Grass Knot could sure help in wallbreaking too.
Well i have not used it but logically if i were to use Greninja with Battle Bond i would use water and dark type moves on it since this is where it hits much harder than Protean Greninja.
Greninja @ Life Orb
Ability: Battle Bond
EVs: 4 Atk / 252 SpA / 252 Spe
Naive Nature
- Hydro Pump
- Dark Pulse
- Gunk Shot
- Water Shuriken
Max speed to outspeed Tapu Koko, stab and Water Shuriken cause it hits faster threats like Choice Scarf Genesect, Landorus-T, Pheromosa etc pretty hard. And Gunk Shot to hit Tapu Fini, Tapu Bulu etc because they resist to both stabs. What do you think?
This won't work cause greninja only gets gunk shot from ORAS move tutor.