Trusty Boomerang, Mana Echoes, Maelstrom Wanderer, and Barret, Avalanche Leader

Prerequisites

• Trusty Boomerang in hand
• Mana Echoes on the battlefield
• Maelstrom Wanderer on the battlefield
• Barret, Avalanche Leader on the battlefield
• at most available

Steps

1. Cast Trusty Boomerang by paying
2. When Trusty Boomerang enters, Barret's triggers, creating a 2/2 Rebel creature token
3. When the Rebel enters, Mana Echoes triggers, adding for each Rebel you control
4. Activate Trusty Boomerang's equip ability by paying , attaching it to the Rebel token
5. Activate the Rebel by paying and tapping it, tapping a creature and returning Trusty Boomerang from the battlefield to your hand
6. Repeat

Results

• Infinite ETB
• Infinite colorless mana
• Infinite storm count
• Infinite tapped creature tokens