Magistrate's Scepter, Coretapper, and Umbral Mantle

Prerequisites

• Magistrate's Scepter on the battlefield
• Coretapper on the battlefield
• Umbral Mantle on the battlefield
• Umbral Mantle attached to Coretapper
• Coretapper does not have summoning sickness
• each turn available

Steps

1. Activate Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter
2. Activate Coretapper by paying and untapping it, giving it +2/+2 until end of turn
3. Repeat from step 1 one additional time
4. Activate Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter
5. Activate Magistrate's Scepter's second ability by tapping and removing three charge counters from it, causing you to take an extra turn after this one
6. Repeat each turn

Results

• Infinite turns