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.
![Karn, Legacy Reforged [March of the Machine: The Aftermath]](http://www.cosmicgames.com/cdn/shop/files/4219b5ea-a252-4d76-a60a-9674340e8ed3.png?v=1759553177&width=1445)
