Malcolm, Keen-Eyed Navigator, Lightning-Rig Crew, and Crab Umbra

Prerequisites

• Malcolm, Keen-Eyed Navigator on the battlefield
• Lightning-Rig Crew on the battlefield
• Crab Umbra on the battlefield
• Crab Umbra attached to Lightning-Rig Crew
• Lightning-Rig Crew does not have summoning sickness

Steps

1. Tap Lightning-Rig Crew to deal 1 damage to each opponent, creating 3 treasure tokens from Malcolm's trigger
2. Sacrifice 3 treasure token for
3. Activate Crab Umbra to untap Lightning-Rig Crew
4. Repeat

Results

• Infinite damage
• Near-infinite sacrifice triggers