Havi, the All-Father, Sakashima the Impostor, and Yahenni, Undying Partisan

Prerequisites

• Havi, the All-Father on the battlefield
• Sakashima the Impostor on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Sakashima the Impostor
2. When Sakashima the Impostor dies, it and Havi trigger
3. Resolve the Havi trigger, returning Sakashima the Impostor from your graveyard to the battlefield as a copy of Havi
4. Resolve the Sakashima the Impostor trigger, returning any legendary creature card with mana value 5 or less from your graveyard to the battlefield
5. Resolve the Yahenni ability
6. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Put all legendary creature cards with mana value 5 or less from your graveyard onto the battlefield