Decimator Web [Mirrodin Besieged] Commander Argentum is Karn's original name

Argentum is Karn's original name for that plane

If a card is exiled with Ugin's Labyrinth

Set: Zendikar Rising Commander Type: Creature — Sphinx Rogue Rarity: Rare Cost: {5}{U}{U} Prowl {3}{U} (You may cast this spell for its prowl cost if you dealt combat damage to a player this turn with a Sphinx or Rogue

put that many 1/1 green Saproling creature tokens into play

but to affirm your subservience

Decimator Web [Mirrodin Besieged] Commander Argentum is Karn's original nameSet: Mirrodin Besieged Type: Artifact Rarity: Rare Cost: {4} {4}, {T}: Target opponent loses 2 life, gets a poison counter, then mills six cards. Mycosynth grew unfettered beneath the black lacuna, metastasizing into a matrix of noxious energy.