Rukarumel, Biologist + Bog Glider + Dryad Arbor + Retreat to Coralhelm + Mortuary

Rukarumel, Biologist

Bog Glider

Dryad Arbor

Retreat to Coralhelm

Mortuary

How it works

1. Activate Bog Glider by tapping it and sacrificing Dryad Arbor.
2. When Dryad Arbor dies, Mortuary triggers, putting Dryad Arbor on top of your library from your graveyard.
3. Resolve the Bog Glider ability from step 1, searching your library for Dryad Arbor and putting it onto the battlefield.
4. When Dryad Arbor enters the battlefield, Retreat to Coralhelm triggers, untapping Bog Glider.
5. Repeat.

This clever loop relies on Rukarumel, Biologist to bridge a vital subtype gap, rewriting Dryad Arbor's characteristics so that it counts as a Mercenary in addition to its other types. With that foundation set, Bog Glider can tap and sacrifice Dryad Arbor to tutor that very same land directly back to the battlefield. Whenever Dryad Arbor goes to the graveyard, Mortuary quietly intercepts it, placing the card back on top of your library where Bog Glider can find it again. Finally, the entry of Dryad Arbor triggers Retreat to Coralhelm, instantly untapping Bog Glider so you can repeat the entire process indefinitely.