Original tag list › Synergy

Once

When this Pokémon evolves / only once after it enters play

36 cards have the "Once" tag (110 including reprints, mirrors and so on): 36 Pokémon and 0 Trainer cards.

Breakdown

By type (Pokémon)

Grass 3
Fire 2
Water 9
Lightning 4
Psychic 6
Fighting 1
Darkness 4
Metal 3
Colorless 4

By expansion

A series

Celestial Guardians 2
Extradimensional Crisis 1
Eevee Grove 2
Wisdom of Sea and Sky 2
Secluded Springs 2

B series

Mega Rising 1
Crimson Blaze 2
Fantastical Parade 3
Mega Shine 2
Pulsing Aura 4
Paradox Drive 7
Everyday Wonders 1
Ruler of the Skies 4
Team Rocket's Ambition 2

C series

Dual Fusion 1

Example cards

10 of the 36 matching cards are shown, chosen so that their effect texts are worded as differently as possible. "Source" shows which part of the card the tag comes from, and "Effect" shows that text.

Card name	ID	Source	Effect
Wimpod	A3_021	Ability	During your first turn, this Pokémon has no Retreat Cost.
Zeraora	A3a_021	Ability	At the end of your first turn, take a Lightning Energy from your Energy Zone and attach it to this Pokémon.
Jolteon	A3b_025	Attack	If this Pokémon evolved during this turn, this attack does 20 more damage.
Mimikyu ex	B2_073	Ability	When this Pokémon is first damaged by an attack after coming into play, prevent that damage.
Drizzile	B3_049	Ability	Once during your turn, when you play this Pokémon from your hand to evolve 1 of your Pokémon, you may do 20 damage to your opponent's Active Pokémon.
Miraidon ex	B3a_019	Ability	Once during your turn, when you put this Pokémon from your hand onto your Bench, you may switch it with your Active Pokémon. If you do, move all of your Energy in play to this Pokémon.
Flutter Mane ex	B3a_026	Attack	If this is the first time this Pokémon has used an attack after coming into play, during your opponent's next turn, they can't use any Trainer cards from their hand.
Dudunsparce	B3a_060	Attack	If this Pokémon evolved from Dunsparce during this turn, discard 2 random Energy from your opponent's Active Pokémon.
Flutter Mane	B3b_035	Attack	If this Pokémon didn't move from the Bench to the Active Spot this turn, this attack does nothing.
Raticate	B4_130	Ability	Once during your turn, when you play this Pokémon from your hand to evolve 1 of your Pokémon, you may look at the top 4 cards of your deck and put all Item cards you find there into your hand. Shuffle the other cards back into your deck.