AbilityFainting Spell
Once during your opponent's turn, if Gengar would be Knocked Out by damage from an attack, you may flip a coin. If heads, the Defending Pokémon is Knocked Out.

Gengar is Pokédex #094, generation 1 (Kanto). Gengar is a Stage 2 Psychic Pokémon with 110 HP. The card lists level 43. The card says it evolves from Haunter. In this catalog that name is Haunter (#093).
Gengar sits at 18/100 in Stormfront, position 18 of 106. Before it is 17 Dusknoir, and after it is 19 Gyarados. The set belongs to the Diamond & Pearl series. It was released on 1 November 2008. The printed size is 100. This checklist is longer, at 106 cards. The listed rarity is Rare.
Fainting Spell is listed as Poké-Power. Once during your opponent's turn, if Gengar would be Knocked Out by damage from an attack, you may flip a coin. If heads, the Defending Pokémon is Knocked Out. The attack Shadow Room lists no damage number. The cost is Psychic. Put 3 damage counters on 1 of your opponent's Pokémon. If that Pokémon has any Poké-Powers, put 6 damage counters on that Pokémon instead. Poltergeist is another attack lists 30× damage. The cost is Psychic, Colorless. Look at your opponent's hand. This attack does 30 damage times the number of Trainer, Supporter, and Stadium cards in your opponent's hand. Weakness is Darkness +30. Resistance is Colorless -20.
Gengar (#094) has 52 other cards in the catalog. Those other cards are in 34 sets. The other printings with a release date run from 1999 to 2026. The earliest other card is Gengar 5/62 in Fossil (1999). That card lists 80 HP, and this one lists 110 HP. The rarity there is Rare Holo, and here it is Rare. Keiji Kinebuchi illustrated that card, and Hajime Kusajima illustrated this one. 48 other cards of Gengar list a different HP.
The illustrator line reads Hajime Kusajima. I count 206 other cards in the catalog with that illustrator.
Stormfront set binder is where a full Stormfront set goes. This card fills one slot there. A generation binder holds one card of each species. Gengar can fill a slot in Generation 1 binder (Kanto). Themed lists that include this exact card are Gengar and the Gastly line. I still need this card.
Once during your opponent's turn, if Gengar would be Knocked Out by damage from an attack, you may flip a coin. If heads, the Defending Pokémon is Knocked Out.
Put 3 damage counters on 1 of your opponent's Pokémon. If that Pokémon has any Poké-Powers, put 6 damage counters on that Pokémon instead.
Look at your opponent's hand. This attack does 30 damage times the number of Trainer, Supporter, and Stadium cards in your opponent's hand.
Stormfront, in the Diamond & Pearl series. It was released on 1 November 2008. The printed size is 100.
18/100. It is entry 18 of 106 in this checklist.
Hajime Kusajima. The catalog lists 206 other cards with that illustrator.
Rare.
Gengar #094, generation 1 (Kanto).
Shadow Room and Poltergeist (30×).