Scaretiller + Retreat to Coralhelm + Ghost Town + Paradise Mantle

Scaretiller

Retreat to Coralhelm

Ghost Town

Paradise Mantle

How it works

1. Activate Scaretiller's ability from Paradise Mantle by tapping Scaretiller, adding one mana of any color.
2. Scaretiller triggers, putting Ghost Town from your hand onto the battlefield tapped.
3. Ghost Town enters the battlefield, triggering Retreat to Coralhelm, untapping Scaretiller.
4. Activate Ghost Town's second ability by paying 0, returning it from the battlefield to your hand.
5. Repeat.