Scuttling Sliver, Trazyn the Infinite, Mana Vault, and Amoeboid Changeling

Prerequisites

• Scuttling Sliver on the battlefield
• Trazyn the Infinite on the battlefield
• Mana Vault in the graveyard
• Amoeboid Changeling on the battlefield

Steps

1. Activate Amoeboid Changeling by tapping it, causing Trazyn to become a Sliver until end of turn
2. Activate Trazyn using Mana Vault's ability by tapping it, adding
3. Activate Trazyn by paying , untapping it
4. Repeat from step 2

Results

• Infinite untap of some creatures you control
• Infinite colorless mana