Siege Elemental [Mystery Booster Playtest Cards] Legacy of Darkness This must be declared when

This must be declared when the monster is destroyed

Set: Secret Lair Drop Promos Type: Legendary Planeswalker — Kaya Rarity: Uncommon Cost: {3}{W/B}{W/B}{W/B} Your opponents and permanents your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof

" —Chainer

you can treat this card as 1 of the Xyz Materials

"It is vain to look for a defense against lightning

Siege Elemental [Mystery Booster Playtest Cards] Legacy of Darkness This must be declared whenSet: Mystery Booster Playtest Cards Type: Creature Elemental Rarity: Rare Cost: {4}{R}{R} Trample Untapped creatures can't block. Tapped creatures can block. TEST CARD Not for constructed play.