Coin of Mastery - Commander: Teenage Mutant Ninja Turtles (Rare) [TMC-38]

Coin of Mastery allows each creature you control to enter the battlefield with extra +1/+1 counters based on the mana spent from artifact sources, enhancing your board presence significantly. Additionally, it can tap to generate Treasure tokens, providing valuable mana ramp for future plays. This card fits well in artifact-centric decks or strategies that focus on creature synergies, enabling you to make the most of your mana resources. However, its higher mana cost means it might be slower to set up in aggressive strategies.