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Mega Altaria ex Greninja Deck Guide

Energy Types
PsychicPsychic
Simbozz Published June 10, 2026 Updated June 10, 2026

Mega Altaria ex Greninja is a creative Psychic toolbox build that pairs Mega Altaria ex's Mega Harmony attack — which scales damage with bench size — and Greninja's Water Shuriken bench-ping ability for relentless chip damage. Giratina's Levitate ability gives it free retreat as long as any energy is attached, making it a perfect pivot piece, while Meloetta's Strange Singing pulls random opposing Pokémon active for clean Sabrina-style disruption. Rare Candy and Protective Poncho round out the consistency package.

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Deck List

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Strengths

  • Mega Altaria ex's Mega Harmony hits 40+30 per benched Pokémon — up to 190+ damage
  • Greninja's Water Shuriken pings 20 damage every turn without Water energy attached
  • Giratina has free retreat thanks to Levitate
  • Meloetta's Strange Singing disrupts the opponent's active spot

Weaknesses

  • Greninja is a Stage 2 — needs Froakie and Rare Candy
  • Mega Altaria ex is a 2-prize liability
  • Vulnerable to Metal counters
  • Bricks without a wide bench for Mega Harmony scaling

Key Matchups

  • Wide bench decks Favored
  • Single-prize aggro Favored
  • Metal aggro Unfavored
  • Stage 2 setup decks Even

Strategy Overview

Open Swablu and Froakie, bench Giratina and Meloetta and attach Psychic energy. Chain Professor's Research / Copycat / Cyrus to dig for Rare Candy and evolve into Greninja for free Water Shuriken pings. Mega Evolve into Mega Altaria ex with a wide bench to swing Mega Harmony for 130+ damage. Detailed matchup data will be updated as the format develops.

Gameplay Video

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Key Cards

Mega Altaria ex

Main attacker — Mega Harmony deals 40 plus 30 per benched Pokémon.

Greninja

Free chip — Water Shuriken pings 20 damage to any opposing Pokémon each turn.

Giratina

Pivot — Levitate gives it free retreat with any energy attached.

Meloetta

Disruption — Strange Singing pulls a random opposing Pokémon active.

Cyrus

Pulls a damaged opposing Pokémon active for a closing knockout.

Early Game

Bench Swablu, Froakie, Giratina and Meloetta, attach Psychic energy and chain draw Supporters. On turn one with Mega Altaria ex Greninja, your priority is finding Mega Altaria ex or Greninja so you can start attaching Psychic energy on schedule. If you open with the wrong basic, search aggressively with Professor's Research or Poké Ball before committing energy you might waste. Bench every basic you intend to evolve as early as possible — Mega Altaria ex and Greninja need time to come online, and an empty bench turn one usually loses you the tempo war. Preserve removal Supporters like Cyrus or Sabrina for the mid game; using them on turn one is rarely worth the lost draw. Against fast aggressive openings hinted at by your unfavored matchups (greninja is a stage 2 — needs froakie and rare candy), bench a pivot so a surprise knockout on the active does not strand your evolution line.

Mid Game

Rare Candy into Greninja for Water Shuriken pings while Mega Evolving into Mega Altaria ex with a wide bench. By the mid game Mega Altaria ex Greninja should have Mega Altaria ex powered and at least one back-up attacker on the bench. This is the window where the deck's core engine — Mega Altaria ex, Greninja, Giratina — has to actively trade prizes. Sequence your attacks so each knockout sets up the next: leave a damaged opposing Pokémon active for Cyrus, or use Sabrina to drag out a benched threat before it can power up. Track your prize trade carefully. Mega Altaria ex Greninja leans on the strengths "Mega Altaria ex's Mega Harmony hits 40+30 per benched Pokémon — up to 190+ damage" and "Greninja's Water Shuriken pings 20 damage every turn without Water energy attached", so push the board state that maximises those lines rather than auto-attacking the active. If you fall behind on board, pivot to a single-prize attacker and use this turn to rebuild instead of giving up a multi-prize knockout.

Late Game

Close with Mega Harmony 130+ swings backed by Cyrus pulls and Meloetta disruption. Late game with Mega Altaria ex Greninja is about closing on your terms. Count your remaining prizes and the opponent's, then build the exact attack sequence that wins before they can stabilise. If you are ahead, deny the comeback: knock out their last realistic attacker or use Sabrina to strand a benched Pokémon that cannot retreat. If you are behind, look for an OHKO line using Mega Altaria ex — Mega Altaria ex Greninja typically wins from behind by chaining a single huge turn rather than grinding back evenly. Be ready to spend every remaining Supporter and energy on the closing turn; holding resources "just in case" after the prize race is decided is the most common way to throw a winning position with this deck.

Mulligan Guide & Opening Priorities

The ideal opener for Mega Altaria ex Greninja is Mega Altaria ex + Greninja in hand with a way to attach Psychic energy on the first turn. Mulligan decisions in Pokémon TCG Pocket are limited, so focus on what you keep: prioritise basics that evolve into your key attackers, plus at least one draw Supporter like Professor's Research or Iono. Hold onto Rare Candy or stage-up pieces even if they look dead early — they enable the explosive mid game this deck depends on. Preserve removal cards (Cyrus, Sabrina) for when the opponent has a damaged or vulnerable bench rather than spending them on the first available target.

Common Mistakes

  • Benching Mega Altaria ex too early without protection, letting the opponent snipe your main attacker before it is powered.
  • Attaching Psychic energy to a Pokémon that will not attack this game instead of building toward your win condition.
  • Spending Cyrus or Sabrina on turn one for tempo when they would have closed a prize two turns later.
  • Evolving on curve into Mega Altaria ex without first checking whether you have the energy to attack the same turn.
  • Ignoring the weakness "Greninja is a Stage 2 — needs Froakie and Rare Candy" and not boarding a pivot or single-prize back-up in unfavored matchups.
  • Auto-attacking the active Pokémon instead of using Sabrina/Cyrus to set up the knockout sequence the deck actually wants.
  • Burning Professor's Research with a full hand and losing the cards you still needed for the closing turn.

Card Replacements

Mega Altaria exNo direct replacement

Mega Altaria ex fills a unique role in Mega Altaria ex Greninja (main attacker — mega harmony deals 40 plus 30 per benched pokémon.). If you do not own it, the deck cannot be rebuilt around a single swap — consider playing a different Psychic archetype until you can craft it.

GreninjaNo direct replacement

Greninja fills a unique role in Mega Altaria ex Greninja (free chip — water shuriken pings 20 damage to any opposing pokémon each turn.). If you do not own it, the deck cannot be rebuilt around a single swap — consider playing a different Psychic archetype until you can craft it.

GiratinaNo direct replacement

Giratina fills a unique role in Mega Altaria ex Greninja (pivot — levitate gives it free retreat with any energy attached.). If you do not own it, the deck cannot be rebuilt around a single swap — consider playing a different Psychic archetype until you can craft it.

Professor's ResearchIono

Iono is a strong universal draw Supporter and slots into nearly any deck if you are missing copies of Professor's Research, though it costs you raw card quantity.

CyrusSabrina

Cyrus pulls a damaged bench Pokémon active; Sabrina lets the opponent choose, but still forces a switch and keeps your closing pressure alive.

Frequently Asked Questions

Is Mega Altaria ex Greninja beginner friendly?

Mega Altaria ex Greninja is a tournament deck build in Tier A. It has a few decision-heavy turns and a real evolution line to manage, so newer players should expect a learning curve before they pilot it well. Read the Early/Mid/Late Game sections above before queuing into ranked.

Is Mega Altaria ex Greninja good for ranked ladder?

Yes — Mega Altaria ex Greninja sits in Tier A of the current meta, and its strengths (Mega Altaria ex's Mega Harmony hits 40+30 per benched Pokémon — up to 190+ damage, Greninja's Water Shuriken pings 20 damage every turn without Water energy attached) line up well against most ladder decks. It is not the absolute top tier, but it is consistent enough to ladder with if you respect its unfavored matchups.

What are the hardest matchups for Mega Altaria ex Greninja?

The toughest matchups are Metal aggro. These decks attack the parts of your plan flagged in the Weaknesses section — usually greninja is a stage 2 — needs froakie and rare candy. Mulligan harder for your fastest opener and lean on single-prize attackers to slow down the prize trade.

What should I craft first for Mega Altaria ex Greninja?

Prioritise Mega Altaria ex and Greninja — these are the cards the deck cannot function without. Draw Supporters (Professor's Research, Iono) and removal (Cyrus, Sabrina) are universal staples and worth crafting even if you later swap archetypes.

Can I play Mega Altaria ex Greninja without the main Psychic engine?

Not really. Mega Altaria ex Greninja is built around Mega Altaria ex and the Psychic energy line — removing that core turns it into a different deck. If you are missing pieces, check the Card Replacements section above for the closest realistic alternatives, or play a budget archetype until you can craft the missing cards.

Is Mega Altaria ex Greninja tournament viable?

Mega Altaria ex Greninja has a real tournament track record — its favored matchups against Wide bench decks and Single-prize aggro cover a meaningful share of the expected field. Bring it if the meta you are reading is heavy on those archetypes.

How long does a game with Mega Altaria ex Greninja usually take?

Most games end inside the Pokémon TCG Pocket turn clock once Mega Altaria ex is online. The slow games are the ones where you miss the evolution or energy attachment on the key turn — those usually decide themselves before turn six.