Mega Greninja ex League Battle Deck Upgrade Guide

Quick verdict

The ratings are TurnZero HQ's own read on a 1 to 5 scale, not an official one. Compare this deck with every other one on the Pokémon battle deck directory.

What's in the box

These are the cards that decide how the deck plays. Each one links to its card page, with its current price.

Mega Greninja ex

Chaos Rising #22

×3. Mortal Shuriken puts 6 damage counters on any Pokémon.

Mega Starmie ex

Perfect Order #21

×2. Nebula Beam does 210 through Weakness and Resistance.

Meowth ex

Perfect Order #62

×1. Finds a Supporter when you bench it.

Froakie

Chaos Rising #20

×4, with 2 Frogadier and 3 Rare Candy.

Surfing Beach

Mega Evolution #129

×3. Switches your Active Water Pokémon once a turn.

Special Red Card

Chaos Rising #82

×2. Cuts your opponent to 3 cards late in the game.

How it plays

Mega Greninja ex is the reason to buy this box. Its Mortal Shuriken Ability, used while it is in the Active Spot, discards a Basic Water Energy from your hand to put 6 damage counters on any of your opponent's Pokémon. Its Ninja Spinner attack does 120 for two Water Energy, or 200 if you return one of those Energy to your hand. Returning the Energy is often free, because Mortal Shuriken wants a Water Energy in your hand next turn anyway.

The deck runs 4 Froakie, 2 Frogadier and 3 Rare Candy, so most games go Froakie straight to Mega Greninja ex on your second turn. Mega Starmie ex is the second attacker: Jetting Blow does 120 and 50 to a Benched Pokémon for one Water Energy, and Nebula Beam does 210 that ignores Weakness, Resistance and effects on the Defending Pokémon. Surfing Beach lets you swap your Active Water Pokémon with a Benched one once a turn, which is how Greninja gets back into the Active Spot to use Mortal Shuriken again.

Meowth ex finds a Supporter when you bench it, and two Mantine use Call for Family to fill your Bench early. Both Megas give up 3 Prize cards when Knocked Out, so the deck wins by taking big Knock Outs faster than your opponent can, not by trading evenly.

Is it Standard legal?

Every card in this deck is Standard legal: the Pokémon are Mega Evolution, Perfect Order and Chaos Rising printings, and the Trainers all carry the I or J mark. It is the newest League Battle Deck and has the longest time before rotation.

Every upgrade card below carries an H, I or J regulation mark, the marks legal in Standard since the April 10, 2026 rotation, checked against our Pokémon card catalog on October 10, 2026. Basic Energy is always legal. See which cards are legal in each format for how regulation marks and reprints decide it.

Upgrade path 1: Make it consistent

The box list is close to a tournament list already, so the first upgrade is about finding Froakie and Rare Candy on time. Buddy-Buddy Poffin puts two Froakie on your Bench at once (both have 70 HP or less), and a fourth Rare Candy means fewer games where Greninja waits a turn.

Dawn finds a Basic, a Stage 1 and a Stage 2 Pokémon in one card, which is a whole Greninja line. It is the best Supporter in a Stage 2 deck that is not drawing cards.

Buddy-Buddy Poffin

Ascended Heroes #184

Two Froakie onto the Bench from one Item.

Rare Candy

Mega Evolution #125

A fourth copy, so Greninja comes down on turn two more often.

Dawn

Phantasmal Flames #87

Froakie, Frogadier and Mega Greninja ex in one search.

Night Stretcher

Ascended Heroes #196

Gets back a Knocked Out Greninja or a Basic Water Energy.

What comes out: One Mantine, one Brock's Scouting, and one Energy Retrieval.

Upgrade path 2: Lean into damage counters

Mortal Shuriken's 6 damage counters set up Knock Outs that other cards can finish. Dusknoir's Cursed Blast puts 13 damage counters on one Pokémon and Knocks Out Dusknoir itself, so one Shuriken plus one Cursed Blast is 190 damage placed anywhere, enough to remove most Pokémon ex in a single turn without attacking.

Budew's Itchy Pollen costs no Energy and stops your opponent from playing Items on their next turn, which buys Greninja the turn it needs. Prime Catcher, the ACE SPEC, brings up the Benched Pokémon you have been softening.

Duskull

Prismatic Evolutions #35

A 2-1-2 Dusknoir line fits beside Greninja's Rare Candy.

Dusknoir

Prismatic Evolutions #37

Cursed Blast: 13 damage counters, then Dusknoir is Knocked Out.

Prime Catcher

Prismatic Evolutions #119

The ACE SPEC. Pulls up the Pokémon you have damaged.

Budew

Ascended Heroes #16

Itchy Pollen costs no Energy: no Items for your opponent next turn.

What comes out: Both Mega Starmie ex and their 3 Staryu make room for the Dusknoir line and Budew.

Upgrade path 3: Protect the Megas

Each Mega gives up 3 Prize cards, so a deck that keeps them alive wins long games. Hero's Cape gives one Pokémon +100 HP, taking Greninja to 450, beyond what most attacks reach in one hit. It is the expensive option; Jumbo Ice Cream heals 80 from an Active Pokémon with three or more Energy, which a Greninja holding Energy for Ninja Spinner often has.

Fezandipiti ex draws 3 cards after one of your Pokémon is Knocked Out, which is the turn this deck most needs cards. Pair it with Unfair Stamp if you are not using another ACE SPEC.

Hero's Cape

Temporal Forces #152

ACE SPEC Tool: +100 HP. The priciest card on this page.

Jumbo Ice Cream

Phantasmal Flames #91

Heals 80 from an Active Pokémon with 3 or more Energy.

Fezandipiti ex

Ascended Heroes #142

Draws 3 the turn after you lose a Pokémon.

Unfair Stamp

Twilight Masquerade #165

ACE SPEC: after a Knock Out, you draw 5 and your opponent draws 2.

What comes out: Special Red Card and one Judge. Pick one ACE SPEC: Hero's Cape or Unfair Stamp, not both.

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Decklist and release details checked against: Bulbapedia , ICv2 , Coded Yellow .