The Jolly Balloon Man, Agatha's Soul Cauldron, Midnight Guard, and Burning-Tree Emissary

Prerequisites

• The Jolly Balloon Man in exile
• Agatha's Soul Cauldron on the battlefield
• Midnight Guard on the battlefield
• Burning-Tree Emissary on the battlefield
• Midnight Guard has at least one +1/+1 counter on it
• Midnight Guard does not have summoning sickness
• available

Steps

1. Activate Midnight Guard using The Jolly Balloon Man's ability by paying and tapping it, creating a token copy of Burning-Tree Emissary that is a 1/1 Balloon with flying and haste in addition to its other types
2. When the Burning-Tree Emissary token enters the battlefield, it and Midnight Guard trigger
3. Resolve the Burning-Tree Emissary token's trigger, adding
4. Resolve the Midnight Guard trigger, untapping it
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite creature tokens with haste
• Infinite token copies of each creature you control with haste except Midnight Guard
• Infinite red mana
• Infinite green mana