Mewtwo V-Union (SWSH161) [Sword & Shield: Black Star Promos] XY142 when a monster effect is

when a monster effect is activated on your opponent's side of the field: You can detach 1 Xyz Material from this card

and it is destroyed during the End Phase

or if this card in its owner's control is destroyed by an opponent's card effect: You can target 1 LIGHT "LV" monster in your Graveyard

each time your opponent Special Summon a monster(s)

This card cannot be Special Summoned except by having 4 or more "Lightsworn" monsters with different names in your Graveyard

Mewtwo V-Union (SWSH161) [Sword & Shield: Black Star Promos] XY142 when a monster effect isSet: Sword & Shield: Black Star Promos Type: Psychic Rarity: Promo Retreat cost: Colorless,Colorless