Karn, Legacy Reforged [March of the Machine: The Aftermath] 31 then put a stun counter

then put a stun counter on each of those creatures

Set: XY: Steam Siege Type: Fire

or R to your mana pool

Set: Sun & Moon: Ultra Prism Type: Supporter Rarity: Promo

Set: The Lord of the Rings: Tales of Middle-Earth Prerelease Promos Type: Legendary Creature — Elf Noble Rarity: Rare Cost: {1}{G}{U} Whenever the Ring tempts you

Karn, Legacy Reforged [March of the Machine: The Aftermath] 31 then put a stun counterSet: March of the Machine: The Aftermath Type: Legendary Artifact Creature Golem Rarity: Mythic Cost: {5} Karn, Legacy Reforged's power and toughness are each equal to the greatest mana value among artifacts you control. At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.