Callidus Assassin (Surge Foil) [Warhammer 40,000] Narset put that many +1/+1 counters

put that many +1/+1 counters on target Halfling or Treefolk

+1: Create an X/X green Phyrexian Horror creature token

any time you could activate a mana ability

Sacrifice Lightshield Array: Creatures you control gain hexproof and indestructible until end of turn

Supporting this hteory

Callidus Assassin (Surge Foil) [Warhammer 40,000] Narset put that many +1/+1 countersSet: 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.