Stalwart Successor, Ashnod's Altar, and Thunderblust

Prerequisites

• Stalwart Successor on the battlefield
• Ashnod's Altar on the battlefield
• Thunderblust on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Thunderblust When Thunderblust dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
2. When Thunderblust enters, Stalwart Successor triggers, putting a +1/+1 counter on Thunderblust Repeat

Results

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