Lagrella, the Magpie, Yannik, Scavenging Sentinel, and Phantom Steed

Prerequisites

• Lagrella, the Magpie in hand or in the command zone
• Yannik, Scavenging Sentinel in exile
• Phantom Steed on the battlefield
• plus enough mana to pay for commander tax, if applicable available

Steps

1. Cast Lagrella by paying and commander tax, if applicable
2. Lagrella enters the battlefield, exiling Phantom Steed
3. Phantom Steed leaves the battlefield, causing Yannik to be returned to the battlefield from exile
4. Yannik enters the battlefield, exiling Lagrella and distributing two +1/+1 counters among any number of target creatures
5. If Lagrella is your commander, choose not to return it to the command zone
6. Lagrella leaves the battlefield, causing Phantom Steed to be returned to the battlefield from exile with two +1/+1 counters on it
7. Phantom Steed enters the battlefield, exiling Yannik
8. Yannik leaves the battlefield, causing Lagrella to be returned to the battlefield from exile
9. Repeat from step 2

Results

• Infinite +1/+1 counters
• Infinite ETB
• Infinite LTB