Battle Deck Upgrade Guide
Mega Diancie ex Mega Battle Deck Upgrade Guide
Two Mega Diancie ex, a Basic Mega that takes 30 less damage, with Wondrous Patch and Grumpig putting its Energy back after every attack.
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.
Shop the Mega Diancie ex Mega Battle Deck on TCGplayer →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 Diancie ex
Phantasmal Flames #41
×2. Garland Ray: 120 for each Energy discarded.
Wondrous Patch
Phantasmal Flames #94
×4. Psychic Energy from the discard to the Bench.
Meloetta
Mega Evolution Black Star Promos #26
Illustration rare promo.
Grumpig
Mega Evolution #63
×2. Attaches Energy from the top 4 cards.
Mystery Garden
Ascended Heroes #194
×2.
Wally's Compassion
Mega Evolution #132
×1. Heals a Mega completely.
How it plays
Mega Diancie ex is a Basic Pokémon, so it can attack on your second turn with no evolving. Garland Ray discards up to 2 Energy from Diancie and does 120 damage for each, so 240 for two. Its Diamond Coat Ability reduces the damage it takes from attacks by 30.
The rest of the deck refills the Energy Garland Ray throws away. Four Wondrous Patch attach a Basic Psychic Energy from your discard pile to a Benched Psychic Pokémon, Grumpig attaches Basic Energy from the top 4 cards of your deck when you evolve into it, and Mystery Garden lets each player discard an Energy to draw up to their count of Psychic Pokémon. Wally's Compassion heals all damage from a Mega Evolution Pokémon ex and returns its Energy to your hand.
Is it Standard legal?
Mostly. The 2 Arven, 1 Iono, 1 Professor's Research and 3 Nest Ball are G prints with no Standard reprint and rotated on April 10, 2026. The rest of the deck carries the H or I mark.
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: Replace the rotated seven
Lillie's Determination replaces Iono and Professor's Research as the main draw. For Arven's job, Team Rocket's Petrel finds any Trainer card, which here is usually Wondrous Patch or Wally's Compassion. Buddy-Buddy Poffin and Ultra Ball replace Nest Ball; Diancie is 270 HP, so it has to come from Ultra Ball or Mega Signal.
Lillie's Determination
Ascended Heroes #192
Replaces Iono and Professor's Research.
Team Rocket's Petrel
Ascended Heroes #207
Finds any Trainer. Replaces Arven.
Mega Signal
Ascended Heroes #193
Finds Mega Diancie ex directly.
Ultra Ball
30th Celebration #128
Replaces Nest Ball.
What comes out: 2 Arven, 1 Iono, 1 Professor's Research, 3 Nest Ball.
Upgrade path 2: Make Diancie harder to Knock Out
Diancie already takes 30 less damage, and each point of HP on top of that is worth more because it gives up 3 Prize cards. Hero's Cape, an ACE SPEC, gives +100 HP, which with Diamond Coat means an attack has to do 400 to Knock Out a 370 HP Diancie. Jumbo Ice Cream heals 80 from an Active Pokémon with three or more Energy, and a second Wally's Compassion resets a damaged Diancie completely.
Latias ex makes every one of your Basic Pokémon free to retreat, so a damaged Diancie can step back to the Bench for Wally's Compassion without spending a Switch.
Hero's Cape
Temporal Forces #152
ACE SPEC Tool: +100 HP. The expensive option.
Wally's Compassion
Mega Evolution #132
A second copy.
Latias ex
Surging Sparks #76
Skyliner: your Basic Pokémon have no Retreat Cost.
Jumbo Ice Cream
Phantasmal Flames #91
Heals 80 from an Active Pokémon with 3 or more Energy.
What comes out: Both Air Balloon, Zacian and Cresselia.
Other battle decks
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Or search, filter and sort all 31 on the battle deck directory.
Decklist and release details checked against: Bulbapedia , PokéGuardian .
Upgrade the deck, then see what you're missing.
Build your upgraded list in TurnZero HQ and it is checked against Standard or Expanded and against the cards you own. Free to start.
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