Zameck Guildmage, and Phantom Train

Prerequisites

• Zameck Guildmage on the battlefield
• Phantom Train on the battlefield
• available

Steps

1. Activate Zameck Guildmage's first ability by paying
2. Activate Phantom Train 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 Zameck Guildmage
4. Resolve the Phantom Train ability
5. Repeat from step 2

Results

• Infinite +1/+1 counters on a creature
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers