Retreat to Coralhelm + Azorius Chancery + Sakura-Tribe Scout

Retreat to Coralhelm

Azorius Chancery

Sakura-Tribe Scout

How it works

1. Activate Sakura-Tribe Scout by tapping it, putting Azorius Chancery from your hand onto the battlefield.
2. When Azorius Chancery enters the battlefield, it and Retreat to Coralhelm trigger.
3. Resolve the Azorius Chancery trigger, returning itself from the battlefield to your hand.
4. Resolve the Retreat to Coralhelm trigger, untapping Sakura-Tribe Scout.
5. Repeat.