Miirym, Sentinel Wyrm | Ganax, Astral Hunter | Goro-Goro, Disciple of Ryusei

(and one other card)

Cast
Ganax by paying ({4} magic symbol) ({R} magic symbol) .
When
Ganax enters the battlefield, it triggers itself,
Mana Echoes and
Miirym.
Resolve the
Mana Echoes trigger, adding at least ({C} magic symbol) ({C} magic symbol) .
Resolve the
Ganax trigger, creating a Treasure token.
Resolve the
Miirym trigger, creating a nonlegendary token copy of
Ganax.
When the token
Ganax enters the battlefield, it triggers itself, the nontoken
Ganax, and
Mana Echoes.
Resolve the
Mana Echoes trigger, adding at least ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) .
Resolve both
Ganax triggers, creating two Treasure tokens.
Move to your combat phase, and declare any modified creature you control as an attacker.
Holding priority, activate three Treasures by tapping and sacrificing them, adding ({1} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Activate
Goro-Goro's second ability by paying ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) , creating a 5/5 Dragon Spirit creature token with flying.
When the Dragon Spirit enters the battlefield, it triggers
Mana Echoes and both
Ganax.
Resolve the
Mana Echoes trigger, adding at least ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) .
Resolve both
Ganax triggers, creating two Treasure tokens.
Activate the Treasures by tapping and sacrificing them, adding ({R} magic symbol) ({R} magic symbol) .
Repeat from step 11.
Once you have infinite tokens, you may use
Goro-Goro's first ability to give them haste.