Dominion Saboteur, Mikaeus, the Unhallowed, and Ashnod's Altar

Prerequisites

• Dominion Saboteur on the battlefield
• Mikaeus, the Unhallowed on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Dominion Saboteur
2. When Dominion Saboteur dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
3. As it enters, choose to have it copy a non-Human you control with a -1/-1 counter on it, and then also enter with a -1/-1 counter on it
4. Repeat

Results

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