Mischief of the Yokai [STBL-EN089] Ultimate Rare OP05-EN002 An Xyz Monster that was

An Xyz Monster that was Summoned using this card on the field as Xyz Material gains this effect

Set: New Phyrexia Type: Legendary Creature — Praetor Rarity: Mythic Cost: {5}{B}{B} Swampwalk (This creature can't be blocked as long as defending player controls a Swamp

Set: Diamond & Pearl: Majestic Dawn Type: Darkness Rarity: Rare Retreat cost: Colorless

Set: Generation Force Card type: Spell Card Rarity: Ultimate Rare If you control no face-up monsters: Pay half of your Life Points

and his citadels lie empty

Mischief of the Yokai [STBL-EN089] Ultimate Rare OP05-EN002 An Xyz Monster that wasSet: Starstrike Blast Card type: Normal Trap Rarity: Ultimate Rare Each face up monster on the field loses 2 Levels, until the End Phase. You can remove from play this card from your Graveyard to select 1 face up monster and reduce its Level by 1, until the End Phase. This effect cannot be activated the same turn this card is sent to the Graveyard.