Callidus Assassin [Warhammer 40,000] Duel Your opponents can't cast spells

Your opponents can't cast spells during combat

where X is the number of descent counters on Descent into Avernus

(You expend 4 as you spend your fourth total mana to cast spells during a turn

leaving nothing but the great Worms' mucous residues

Callidus Assassin [Warhammer 40,000] Duel Your opponents can't cast spellsSet: Warhammer 40,000 Type: Creature Human Shapeshifter Assassin Rarity: Rare Cost: {4}{U}{B} Flash Polymorphine You may have Callidus Assassin enter the battlefield tapped as a copy of any creature on the battlefield, except it has When this creature enters the battlefield, destroy up to one other target creature with the same name as this creature.