Omnath, Locus of the Roil + Abundance + Retreat to Coralhelm + Llanowar Scout

Omnath, Locus of the Roil

Abundance

Retreat to Coralhelm

Llanowar Scout

How it works

1. Activate Llanowar Scout by tapping it, putting a land card from your hand onto the battlefield.
2. When the land enters the battlefield, Retreat to Coralhelm and Omnath's second ability triggers.
3. Resolve the Retreat to Coralhelm trigger, untapping Llanowar Scout.
4. Resolve the Omnath trigger, putting a +1/+1 counter on an Elemental you control, and then causing you to reveal cards from the top of your library until you reveal a land card and put it into your hand due to Abundance.
5. Repeat.