Activate Bog Glider by tapping it and sacrificing Dryad Arbor.
When Dryad Arbor dies, Mortuary and Bog Glider trigger.
Resolve the Bog Glider trigger, untapping it.
Resolve the Mortuary trigger, putting Dryad Arbor on top of your library from your graveyard.
Resolve the Bog Glider ability from step 1, searching your library for Dryad Arbor and putting it onto the battlefield.
Repeat.
This clever loop turns a modest land into a self-sustaining engine by transforming our battlefield interactions through Rukarumel, Biologist, which turns all our creatures into Slivers and—crucially for Thornbite Staff—Shamans. With Thornbite Staff equipped to Bog Glider, sacrificing Dryad Arbor triggers both Mortuary to cycle the Arbor right back to the top of our library and Bog Glider's own ability to fetch it back onto the battlefield. Because Bog Glider is a Shaman, every time Dryad Arbor dies and re-enters, the Staff untaps the Glider to ready it for the next sacrifice.