Scaretiller + Retreat to Coralhelm + Oboro, Palace in the Clouds + Paradise Mantle

Scaretiller

Retreat to Coralhelm

Oboro, Palace in the Clouds

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 Oboro from your hand onto the battlefield tapped.
3. Oboro enters the battlefield, triggering Retreat to Coralhelm, untapping Scaretiller.
4. Activate Oboro's second ability by paying 1, returning it from the battlefield to your hand.
5. Repeat.