* Ash-Greninja is a fearsome offensive wallbreaker that can hit insanely hard with its Choice Specs-boosted STAB attacks.
*Water Shuriken, is a special attack with a guaranteed 60 Base Power after Greninja transforms, making Ash-Greninja a very effective revenge killer.
* Ash-Greninja's frightening offensive stats make it a pain to switch into its STAB moves, and the Speed increase also lets it outspeed otherwise faster Pokemon such as Tapu Koko and Weavilei
* Less prediction is required with Ash-Greninja than Protean Greninja, as it relies upon its main STAB attacks instead of its coverage moves.
* Ash-Greninja doesn't transform until it KOes something, meaning that you are forced to use a Pokemon that's quite weak by OU standards until it knocks a foe out.
* Ash-Greninja is very frail, even for an offensive Pokemon, so it can't switch into anything very well aside from weak resisted hits like Scald from Toxapex and Psychic-type moves.
name: Choice Specs
move 1: Water Shuriken
move 2: Dark Pulse
move 3: Hydro Pump
move 4: U-turn
item: Choice Specs
ability: Battle Bond
evs: 4 Def / 252 SpA / 252 Spe
* Water Shuriken is a very effective priority move, knocking out faster sweepers such as Pheromosa in one turn and revenge killing weakened Pokemon.
* Dark Pulse is the most spammable STAB move on this set, 2HKOing virtually every neutral target in the tier and having very few sturdy switch-ins.
* Hydro Pump is the best secondary STAB move because it allows you to nuke the opposing team in situations where they lack good Water-type switch-ins
* U-turn is useful because Greninja forces a lot of switches, and it allows you to maintain momentum when your opponent switches into a Greninja check like Tapu Bulu without forcing you to predict.
* Maximum Special Attack coupled with maximum Speed and a Timid nature maximizes Greninja's damage output while allowing it to outspeed fast Pokemon such as Tapu Koko and Weavile after transforming as well as Starmie and Mega Metagross before transforming.
* Choice Specs allows Ash-Greninja to fire off its STAB attacks with a lot of power and ensures that it doesn't get worn down when spamming U-turn.
* Use U-turn when the provided momentum will be more significant than getting damage against a Pokemon that can wall it, such as when your opponent has a defensive Tapu Fini to freely switch into Ash-Greninja, and when it's obvious that you have an opportunity to punish your opponent sacrificing a Pokemon.
* Before transforming, be aggressive with bringing Greninja into weakened targets that it can revenge kill so that your opponent is forced into an unfavorable position.
* Try to bring in Ash-Greninja with free switches or with VoltTurn users to give it as many opportunities to fire off its Choice Specs-boosted STAB moves.
* Use Water Shuriken to revenge kill weakened Pokemon and offensive threats like Pheromosa that are OHKOed by it.
* You can play mind games with your opponent, bluffing Protean Greninja early-game and double switching out to confuse them until their team has been worn down to a point where they have to sacrifice a Pokemon to you.
* Lastly, you will rarely use U-turn after transforming due to just how powerful Ash-Greninja's attacks are.
* Swords Dance Landorus-T with Flynium Z can break through defensive Water-types that can be problematic for Ash-Greninja to deal with as well as surprising Grass-types with Fly.
* Dugtrio can be a very effective teammate for its ability to trap and cripple or KO Pokemon such as Tapu Koko and Chansey that are problematic for Ash-Greninja to deal with normally.
* Pokemon that use Volt Switch or U-turn such as Genesect and Tapu Koko can form a momentum core with Ash-Greninja and give it opportunities to switch in and fire off its STAB moves.
* Entry hazard support is very valuable for Ash-Greninja, as it punishes the many switches that Greninja forces.
* General physical wallbreakers such as Choice Band Kyurem-B are very good partners to beat the normal defensive answers to Greninja such as Chansey.
* Tapu Fini utilizing Nature's Madness makes an excellent teammate for Greninja because it can cripple Pokemon such as Tapu Bulu to a point that they can't switch into Ash-Greninja.
* Offensive Psychic-types, most notably Mega Alakazam and Tapu Lele, (AC) make excellent partners for Ash-Greninja, (AC) as they can remove Toxapex for it as well as pressuring blanket checks to special attackers. However, it should be noted that Tapu Lele's ability prevents Water Shuriken from being used for a short amount of time.
* Life Orb is an option, but it wears Ash-Greninja down quickly and lacks the immediate power of Choice Specs.
* A set focused on coverage moves such as Extrasensory, Grass Knot, and Ice Beam as opposed to Greninja's STAB combination could be used, but it is outclassed by Protean Greninja.
Checks and Counters
**Preventing Transformation**: Ash-Greninja is a nearly unstoppable wallbreaker after it transforms, so preventing its transformation is the most effective way to deal with it. Aggressively pivoting around it and avoiding using death fodder are just a couple of the ways that you can accomplish this.
**Bulky Water-types**: Tapu Fini can switch into Ash-Greninja with ease and threaten to KO it with Moonblast. Specially defensive Toxapex is also particularly annoying to deal with because it can easily switch into Greninja's Choice Specs-boosted Dark Pulse many times throughout the match, keeping it from transforming.
**Bulky Grass-types**: Grass-type Pokemon such as Assault Vest Tangrowth and Tapu Bulu can come in on both of Ash-Greninja's STAB moves and threaten to OHKO it with STAB Grass-type attacks in return. However, Tapu Bulu has to be careful of switching in when Stealth Rock is up because Choice Specs-boosted Hydro Pump from Ash-Greninja does a hefty chunk of damage.
**Faster Pokemon**: Faster Pokemon like Pheromosa, Mega Alakazam, and Choice Scarf Genesect, can revenge kill Ash-Greninja, but they have to be wary of switching directly into it. The same applies to Tapu Koko, except it can only revenge kill Greninja before transformation due to its lower Speed. Choice Scarf Keldeo in particular resists Ash-Greninja's STAB combination, and it can outspeed and threaten to KO with Secret Sword.
**Priority**: Priority moves such as Choice Band Genesect's Extreme Speed and Breloom's and as well as Conkeldurr's Mach Punch can potentially revenge kill Ash-Greninja, but its resistances to common priority moves such as Sucker Punch and Bullet Punch limit the pool of priority moves that can KO it from high HP.