Saffi Eriksdotter, and Crypt Champion

Prerequisites

• Saffi Eriksdotter on the battlefield
• Crypt Champion in hand
• in non-red mana available

Steps

1. Cast Crypt Champion by paying , ensuring not to spend to cast it
2. Crypt Champion enters the battlefield, triggering its first and second abilities
3. Holding priority, activate Saffi by sacrificing it, targeting Crypt Champion
4. Resolve the first Crypt Champion trigger, returning Saffi from your graveyard to the battlefield
5. Resolve the second Crypt Champion trigger, sacrificing it
6. Saffi triggers, returning Crypt Champion from your graveyard to the battlefield
7. Repeat from step 2

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers