Fertilid + Nissa, Resurgent Animist + Archelos, Lagoon Mystic + Thranduil's Company

Fertilid

Nissa, Resurgent Animist

Archelos, Lagoon Mystic

Thranduil's Company

How it works

1. Activate Fertilid by paying 1 and removing a +1/+1 counter from it, causing you to search your library for a basic land card and put it on the battlefield untapped due to Archelos.
2. When the basic land enters, Nissa and Thranduil's Company trigger.
3. Resolve the Nissa trigger, adding .
4. Resolve the Thranduil's Company trigger, putting two +1/+1 counters on Fertilid.
5. Activate the basic land by tapping it, adding 1.
6. Repeat.

This brilliant loop feeds directly on its own triggers to sweep every basic land straight out of your library. While Archelos, Lagoon Mystic ensures the fetched lands enter untapped so they can immediately tap for mana, Nissa, Resurgent Animist refunds your activation costs and digs through your deck for Elves and Elementals. Meanwhile, Thranduil's Company provides the vital +1/+1 counters needed to constantly replenish Fertilid, whose activated ability keeps the whole engine turning over and over.