Ashnod's Altar, and Combine Guildmage

Prerequisites

• Ashnod's Altar on the battlefield
• Combine Guildmage on the battlefield
• available

Steps

1. Activate Combine Guildmage's first ability by paying and tapping it
2. Activate Ashnod's Altar by sacrificing the persist creature
3. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Combine Guildmage
4. Repeat from step 2

Results

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