
The best moveset for Greninja in the current competitive meta typically features the moves Protect, Dark Pulse, Water Shuriken, Ice Beam.
In the Pokémon Champions meta, Greninja can be countered by exploiting its weaknesses (bug 2x, electric 2x, fairy 2x, fighting 2x, grass 2x) and using effective check/counter teams.
The best item for Greninja is typically Greninjite, based on high-level tournament and ladder stats.