AttackPhoton Wave
During your opponent's next turn, any damage done by attacks from the Defending Pokémon is reduced by 30 (before applying Weakness and Resistance).

BREAKthrough is a set in the XY series. It was released on November 4, 2015. The printed size is 162. This checklist is longer, at 165 cards. Mewtwo-EX is 163/162, in position 164 of 165 on this checklist. Before it is 162 Giovanni's Scheme, and after it is 164 Mewtwo-EX. The collector number is above the printed set size of 162. The listed rarity is Rare Secret.
Mewtwo-EX is a Basic EX Psychic Pokémon with 170 HP. In the Pokédex this is Mewtwo (#150), generation 1 (Kanto). The card lists M Mewtwo-EX, Mewtwo (#150) under evolves to.
Mitsuhiro Arita illustrated this card. The same name is on 721 other cards in the catalog.
Mewtwo (#150) has 88 other cards in the catalog. Those other cards are in 42 sets. The other printings with a release date run from 1999 to 2026. The earliest other card is Mewtwo 10/102 in Base (1999). That card is named Mewtwo, while this one is Mewtwo-EX. That card lists 60 HP, and this one lists 170 HP. The rarity there is Rare Holo, and here it is Rare Secret. Ken Sugimori illustrated that card, and Mitsuhiro Arita illustrated this one. Retreat cost there is 3, and here it is 2. 75 other cards of Mewtwo list a different HP.
The attack Photon Wave lists 30 damage. The cost is Colorless, Colorless. During your opponent's next turn, any damage done by attacks from the Defending Pokémon is reduced by 30 (before applying Weakness and Resistance). Psyburn is another attack lists 120 damage. The cost is Psychic, Psychic, Colorless, Colorless. Weakness is Psychic ×2. Retreat cost is 2. The card text says: Pokémon-EX rule: When a Pokémon-EX has been Knocked Out, your opponent takes 2 Prize cards.
I keep a set binder for BREAKthrough, meant to hold every card of that set. This card is one slot in the BREAKthrough set binder. A generation binder holds one card of each species. Mewtwo can fill a slot in Generation 1 binder (Kanto). Themed lists that include this exact card are Mitsuhiro Arita cards and Mew and Mewtwo. I still need this card.
During your opponent's next turn, any damage done by attacks from the Defending Pokémon is reduced by 30 (before applying Weakness and Resistance).
Pokémon-EX rule: When a Pokémon-EX has been Knocked Out, your opponent takes 2 Prize cards.
BREAKthrough, in the XY series. It was released on November 4, 2015. The printed size is 162.
163/162. It is entry 164 of 165 in this checklist.
Mitsuhiro Arita. The catalog lists 721 other cards with that illustrator.
Rare Secret.
Mewtwo #150, generation 1 (Kanto).
Photon Wave (30) and Psyburn (120).