Mikaeus, the Unhallowed, Ashnod's Altar, and Glen Elendra Guardian

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Ashnod's Altar on the battlefield
• Glen Elendra Guardian on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Glen Elendra Guardian
2. When Glen Elendra Guardian dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to its replacement effect
3. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite colorless mana
• Infinite death triggers
• Infinite sacrifice triggers