Malcolm, Keen-Eyed Navigator, Leyline of Transformation, and Reckless Fireweaver

Prerequisites

• Malcolm, Keen-Eyed Navigator on the battlefield
• Leyline of Transformation on the battlefield
• Reckless Fireweaver on the battlefield

Steps

1. Cause an artifact to enter the battlefield under your control
2. Reckless Fireweaver triggers, dealing 1 damage to each opponent
3. Malcolm triggers, as Reckless Fireweaver is a Pirate due to Leyline of Transformation, creating a Treasure token for each opponent dealt damage this way
4. When the Treasure(s) enter, Reckless Fireweaver triggers that many times
5. Resolve the first Reckless Fireweaver trigger, dealing 1 damage to each opponent
6. Repeat from step 3

Results

• Infinite colored mana
• Infinite damage
• Infinite Treasure tokens