Tazri, Stalwart Survivor, Duergar Mine-Captain, and Zirda, the Dawnwaker

Prerequisites

• Tazri, Stalwart Survivor on the battlefield
• Duergar Mine-Captain on the battlefield
• Zirda, the Dawnwaker on the battlefield
• Duergar Mine-Captain does not have summoning sickness

Steps

1. Activate Duergar Mine-Captain by tapping it, adding that can only be spent to activate abilities
2. Activate Duergar Mine-Captain by paying and untapping it, giving attacking creatures +1/+0 until end of turn
3. Repeat

Results

• Infinitely powerful attacking creatures until end of turn