Activate Phyrexian Altar by sacrificing the additional creature, adding one mana of any color.
Cast the creature from your graveyard by paying its mana cost. It will not enter with a finality counter on it due to Solemnity.
Repeat.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Infinite storm count

Leonardo, Sewer Samurai

Solemnity

Phyrexian Altar

Activate Ashnod's Altar by sacrificing Ornithopter.
Cast Ornithopter from your graveyard by paying {0}. It will not enter with a finality counter on it due to Solemnity.
Repeat.

Infinite colorless mana

Ashnod's Altar

Ornithopter

Activate Grinding Station by tapping it and sacrificing Ornithopter.
Cast Ornithopter from your graveyard by paying {0}. It will not enter with a finality counter on it due to Solemnity.
When Ornithopter enters, Grinding Station triggers, untapping Grinding Station.
Repeat.

Infinite mill

Infinite self-mill

Infinite mana creatures you control can produce

Infinite untap of creatures you control

Grinding Station

Cast Tatterkite from your graveyard by paying {1} due to Semblance Anvil. It won't enter with a finality counter on it due to its static ability.
Activate Ashnod's Altar by sacrificing Tatterkite, adding {C}{C}
Repeat.

Tatterkite

Semblance Anvil

Cast Tatterkite from your graveyard by paying {2} due to Cloud Key. It won't enter with a finality counter on it due to its static ability.
Activate Ashnod's Altar by sacrificing Tatterkite, adding {C}{C}
Repeat.

Cloud Key

Cast Tatterkite from your graveyard by paying {0} due to Ezzaroot Channeler. It won't enter with a finality counter on it due to its static ability.
Activate Altar of Dementia by sacrificing Tatterkite.
Repeat.

Combos with "Leonardo, Sewer Samurai"