Valkyrie's Call, Amoeboid Changeling, Spawning Pit, and Bounding Krasis

Prerequisites

• Valkyrie's Call on the battlefield
• Amoeboid Changeling on the battlefield
• Spawning Pit on the battlefield
• Bounding Krasis on the battlefield

Steps

1. Activate Amoeboid Changeling's second ability by tapping it, removing all creature types from Bounding Krasis
2. Activate Spawning Pit by sacrificing Bounding Krasis
3. When Bounding Krasis dies, Valkyrie's Call triggers, returning Bounding Krasis from your graveyard to the battlefield as an Angel with flying and a +1/+1 counter on it
4. When Bounding Krasis enters the battlefield, it triggers, untapping Amoeboid Changeling
5. Resolve the Spawning Pit ability, putting a charge counter on it
6. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite charge counters on a permanent