Francisco, Fowl Marauder, Walking Ballista, and Agatha's Soul Cauldron

Prerequisites

• Francisco, Fowl Marauder on the battlefield
• Walking Ballista in exile
• Agatha's Soul Cauldron on the battlefield
• You have a nonland card on top of your library
• Francisco has at least one +1/+1 counter on it

Steps

1. Activate Francisco using Walking Ballista's second ability by removing a +1/+1 counter on it, dealing 1 damage to an opponent
2. Francisco triggers, causing you to reveal the top card of your library, put a +1/+1 counter on Francisco and put the card back on top of your library
3. Repeat

Results

• Infinite damage