Tourach's Chant, Dryad Arbor, Mikaeus, the Unhallowed, and Pandemonium

Prerequisites

• Tourach's Chant on the battlefield
• Dryad Arbor in hand
• Mikaeus, the Unhallowed on the battlefield
• Pandemonium on the battlefield

Steps

1. Play Dryad Arbor
2. When Dryad Arbor enters, Tourach's Chant and Pandemonium trigger
3. Resolve the Tourach's Chant trigger, putting a -1/-1 counter on Dryad Arbor
4. Dryad Arbor dies as a state-based action due to having 0 toughness, triggering its undying ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it
5. When Dryad Arbor enters, Tourach's Chant and Pandemonium trigger
6. Resolve the Tourach's Chant trigger, putting a -1/-1 counter on Dryad Arbor
7. Resolve the Pandemonium trigger, dealing damage to Dryad Arbor
8. Repeat from step 4

Results

• Infinite LTB
• Infinite ETB
• Infinite death triggers
• Infinite landfall triggers