Fire Nation Palace by paying ({1} magic symbol) ({R} magic symbol) and tapping it, giving
Hellkite Charger firebending 4 until end of turn.
Declare
Hellkite Charger as an attacker, triggering its firebending ability, its regular ability and
Avatar Roku.
Resolve the
Avatar Roku and firebending triggers, adding ten ({R} magic symbol) .
Resolve the second
Hellkite Charger trigger, causing you to pay ({5} magic symbol) ({R} magic symbol) ({R} magic symbol) to untap all attacking creatures and to get an additional combat phase after this one.
Repeat from step 2.
Results
Infinite combat phases.
Infinite red mana.
Infinitely powerful creatures you control until end of turn.