Cast Agadeem's Awakening paying {4}{B}{B}{B} returning Priest of Gix and Archaeomancer to the battlefield.
Priest of Gix enters, adding six {B}.
Archaeomancer enters, return Agadeem's Awakening from your graveyard to your hand.
Sacrifice Priest of Gix and Archaeomancer to Ashnod's Altar to add {C}{C}{C}{C}.
Repeat.

Infinite black mana

Infinite colorless mana

Infinite creature ETB

Infinite creature LTB

Infinite death triggers

Infinite creature sacrifice triggers

Infinite storm count

Ashnod's Altar

Priest of Gix

Archaeomancer

Agadeem's Awakening // Agadeem, the Undercrypt

Panharmonicon

Yarok, the Desecrated

Combos with "Agadeem's Awakening // Agadeem, the Undercrypt"