Greninja (41/146) [XY: Base Set] Ultimate Rare until the end of the

until the end of the Damage Step any effect damage you take becomes 0

Shatterskull Pass is a pretty distant second

Set: XY: Ancient Origins Type: Psychic Rarity: Promo Retreat cost: Colorless

Set: Duel Terminal 5 Card type: Fusion/Effect Monster Rarity: Ultra Rare Attack: 2500 Defense: 1300 "Gem-Knight Garnet" + 1 "Gem-Knight" monster This monster can only be Special Summon by Fusion Summoned (from the Extra Deck) using the above cards as Fusion Material Monsters

Set: Judgment Type: Creature — Cat Beast Spirit Rarity: Rare Cost: {5}{G}{W} Trample

Greninja (41/146) [XY: Base Set] Ultimate Rare until the end of theSet: XY: Base Set Type: Water Rarity: Holo Rare Retreat cost: Colorless