Thornbite Staff attached to Feldon of the Third Path.
Feldon of the Third Path does not have summoning sickness.
({2} magic symbol) ({R} magic symbol) available.
Steps
Activate Feldon of the Third Path by paying ({2} magic symbol) ({R} magic symbol) and tapping it, creating a token copy of Su-Chi Cave Guard with haste.
Activate Thermopod's second ability by sacrificing the Su-Chi Cave Guard token, adding ({R} magic symbol) .
When the Su-Chi Cave Guard token dies, it and Feldon of the Third Path trigger.
Resolve the Feldon of the Third Path trigger, untapping it.