Oboro Breezecaller + Retreat to Coralhelm + Llanowar Scout

Oboro Breezecaller

Retreat to Coralhelm

Llanowar Scout

How it works

1. Activate Llanowar Scout by tapping it, putting a land from your hand onto the battlefield.
2. When the land enters the battlefield, Retreat to Coralhelm triggers, untapping Llanowar Scout.
3. Activate the land and another land by tapping them, adding at least 2.
4. Activate Oboro Breezecaller by paying 2 and returning a land from the battlefield to your hand, untapping another land.
5. Repeat.