Declare any modified creature you control as an attacker.
Holding priority, activate Goro-Goro by paying {5}, creating a 5/5 Dragon Spirit creature token.
The Dragon Spirit enters the battlefield, triggering Mana Echoes, adding at least {5}.
Repeat from step 2.
Once you have infinite tokens, you may use Goro-Goro's first ability to give them haste.

Infinite colored mana

Infinite colorless mana

Infinite creature tokens with haste

Infinite creature ETB

Goro-Goro, Disciple of Ryusei

Mana Echoes

Mycosynth Lattice

Declare any modified creature you control as an attacker.
Holding priority, activate Goro-Goro's second ability by paying {3}{R}{R}, creating a 5/5 Dragon Spirit creature token with flying.
When the Dragon Spirit enters the battlefield, it triggers Mana Echoes and Ganax.
Resolve the Mana Echoes trigger, adding at least {C}{C}{C}.
Resolve the Ganax trigger, creating a Treasure token.
Activate the Treasure by tapping and sacrificing it, adding {R}{R}.
Repeat from step 2.
 Once you have infinite tokens, you may use Goro-Goro's first ability to give them haste.

Ganax, Astral Hunter

Goldspan Dragon

Infinite card draw

Infinite draw triggers

Chromatic Orrery

Declare any modified creature you control as an attacker.
Holding priority, activate Goro-Goro's second ability by paying {3}{R}{R}, creating a 5/5 Dragon Spirit creature token with flying.
When the Dragon Spirit enters the battlefield, it triggers Mana Echoes and Ganax.
Resolve the Mana Echoes trigger, adding at least {C}{C}{C}.
Resolve the Ganax trigger, creating two Treasure tokens.
Activate the Treasures by tapping and sacrificing them, adding {R}{R}.
Repeat from step 2.
 Once you have infinite tokens, you may use Goro-Goro's first ability to give them haste.

Xorn

Jolene, the Plunder Queen

Cast Ganax by paying {4}{R}.
When Ganax enters the battlefield, it triggers itself, Mana Echoes and Miirym.
Resolve the Mana Echoes trigger, adding at least {C}{C}.
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}{C}{C}.
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}{R}{R}.
Activate Goro-Goro's second ability by paying {3}{R}{R}, 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}{C}{C}{C}.
Resolve both Ganax triggers, creating two Treasure tokens.
Activate the Treasures by tapping and sacrificing them, adding {R}{R}.
Repeat from step 11.
Once you have infinite tokens, you may use Goro-Goro's first ability to give them haste.

Combos with "Goro-Goro, Disciple of Ryusei"