Aethersnipe, Gwenna, Eyes of Gaea, and Birgi, God of Storytelling // Harnfel, Horn of Bounty

Prerequisites

• Aethersnipe in hand
• Gwenna, Eyes of Gaea on the battlefield
• Birgi, God of Storytelling // Harnfel, Horn of Bounty on the battlefield
• available

Steps

1. Activate Gwenna by tapping it, adding that can only be spent to cast creature spells or activate abilities of creatures
2. Cast Aethersnipe for its evoke cost by paying
3. Gwenna and Birgi trigger
4. Resolve the Birgi trigger, adding
5. Resolve the Gwenna trigger, putting a +1/+1 counter on it and untapping it
6. When Aethersnipe enters the battlefield, its first ability and evoke ability trigger
7. Resolve the first Aethersnipe trigger, returning it from the battlefield to your hand
8. Resolve the second Aethersnipe trigger, failing to sacrifice it as it is no longer on the battlefield
9. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite storm count
• Infinite +1/+1 counters on a creature