Activate Vat of Rebirth by paying {2}{B}, tapping it and removing four oil counters from it, returning Myr Battlesphere from your graveyard to the battlefield.
Myr Battlesphere enters the battlefield, creating four 1/1 Myr artifact creature tokens.
Activate Clock of Omens by tapping two Myrs, untapping Vat of Rebirth.
Activate Phyrexian Altar four times by sacrificing Myr Battlesphere and three Myr tokens, adding {3}{B}.
Myr Battlesphere and the Myrs die, triggering Vat of Rebirth four times, putting four oil counters on it.
Repeat.

Infinite creature ETB

Infinite colored mana

Infinite creature tokens

Infinite death triggers

Infinite creature LTB

Infinite mana artifacts you control can produce

Infinite creature sacrifice triggers

Infinite untap of artifacts you control

Vat of Rebirth

Myr Battlesphere

Clock of Omens

Phyrexian Altar

Activate Vat of Rebirth by paying {2}{B}, tapping it and removing four oil counters from it, returning Myr Battlesphere from your graveyard to the battlefield.
Myr Battlesphere enters the battlefield, creating four 1/1 Myr artifact creature tokens.
Activate Phyrexian Altar four times by sacrificing Myr Battlesphere and three Myr tokens, adding {3}{B}.
Myr Battlesphere and the Myrs die, triggering Vat of Rebirth and Dross Scorpion four times.
Resolve all Dross Scorpion triggers, untapping Vat of Rebirth and up to three other artifacts you control.
Resolve all Vat of Rebirth triggers, putting four oil counters on it.
Repeat.

Dross Scorpion

Activate Vat of Rebirth by paying {2}{B}, tapping it, and removing four oil counters from it, returning Vishgraz from your graveyard to the battlefield.
Vishgraz triggers, creating three 1/1 Phyrexian Mite artifact creature tokens.
Activate Phyrexian Altar by sacrificing a Phyrexian Mite token, adding {B}.
Dross Scorpion and Vat of Rebirth trigger.
Resolve Dross Scorpion's trigger, untapping Vat of Rebirth or another artifact.
Resolve Vat of Rebirth's trigger, putting an oil counter on it.
Repeat steps 3 through 6 one additional time.
Activate Phyrexian Altar by sacrificing Vishgraz.
Vat of Rebirth triggers, causing you to put an oil counter on it.
Repeat.
Once you have infinite creature tokens, you may activate Phyrexian Altar any number of times, adding any amount of colored mana.

Vishgraz, the Doomhive

Combos with "Vat of Rebirth"