Activate Trazyn the Infinite using Firemind Vessel's ability by tapping it, adding two mana of differing colors.
Activate Trazyn the Infinite using Staff of Domination's first ability by paying {1}, untapping it.
Repeat.
Once you have infinite mana, you may use it to activate any of Staff of Domination's abilities using Trazyn the Infinite.

Infinite card draw

Infinite colored mana

Infinite draw triggers

Infinite lifegain

Infinite lifegain triggers

Infinite mana creatures you control can produce

Infinite untap of creatures you control

Trazyn the Infinite

Staff of Domination

Firemind Vessel

Activate Myr Welder using Firemind Vessel's ability by tapping it, adding two mana of different colors.
Activate Myr Welder using Staff of Domination's first ability by paying {1}, untapping it.
Repeat.

Myr Welder

Activate Trazyn using Firemind Vessel's ability by tapping it, adding {2}.
Activate Trazyn using Pili-Pala's ability by paying {2} and untapping it, adding one mana of any color.
Repeat.

Pili-Pala

Activate Trazyn using Firemind Vessel's ability by tapping it, adding {2}.
Activate Trazyn using Farmstead Gleaner's ability by paying {2} and untapping it, putting a +1/+1 counter on Trazyn.
Repeat.

Infinite +1/+1 counters on a creature

Farmstead Gleaner

Activate Firemind Vessel by tapping it, adding {2}
Activate Pentavus's first ability by paying {1} and removing a +1/+1 counter from it, creating a 1/1 Pentavite creature token.
Activate Pentavus's second ability by paying {1} and sacrificing the Pentavite.
When the Pentavite dies, Dross Scorpion triggers, untapping Firemind Vessel.
Resolve the Pentavus ability, putting a +1/+1 counter on it.
Repeat.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Pentavus

Dross Scorpion

Activate Firemind Vessel by tapping it, two mana of different colors.
Activate Voltaic Key by paying {1} and tapping it, targeting Firemind Vessel.
Locus of Enlightenment triggers, copying Voltaic Key's ability, targeting Voltaic Key.
Resolve both Voltaic Key abilities, untapping it and Firemind Vessel.
Repeat.

Infinite mana artifacts you control can produce

Infinite untap of artifacts you control

The Enigma Jewel // Locus of Enlightenment

Voltaic Key

Activate Greater Good by sacrificing The Swarmlord.
Choose to return The Swarmlord to the command zone from your graveyard.
The Swarmlord dies, causing you to draw a card.
Resolve the Greater Good ability, causing you to draw a number of cards equal to The Swarmlord's power, and then discard three cards.
Activate Firemind Vessel by tapping it, adding two mana of different colors.
Activate Mind over Matter by discarding a card, untapping Firemind Vessel.
Repeat from step 5 until you have enough mana to cast The Swarmlord.
Cast The Swarmlord from the command zone by paying {3}{U}{R}{G} and commander tax, causing The Swarmlord to enter the battlefield with two +1/+1 counters for each time you've cast it from the command zone this game.
Repeat.

Infinite looting

Infinite self-discard triggers

Near-infinite death triggers

Near-infinite ETB

Near-infinite LTB

Near-infinite sacrifice triggers

The Swarmlord

Greater Good

Mind Over Matter

Activate Idris using Firemind Vessel's ability by tapping it, adding {1}{U}.
Activate Pemmin's Aura's first ability by paying {U}, untapping Idris.
Repeat.

Infinite black mana

Infinite green mana

Infinite red mana

Infinite white mana

Idris, Soul of the TARDIS

Pemmin's Aura

Activate Idris using Firemind Vessel's ability by tapping it, adding {1}{U}.
Activate Freed from the Real's second ability by paying {U}, untapping Idris.
Repeat.

Freed from the Real

Activate Tezzeret's first loyalty ability by putting a loyalty counter on it, targeting Firemind Vessel and The Peregrine Dynamo.
Holding priority, activate Firemind Vessel by tapping it, adding two mana of differing colors.
Activate The Peregrine Dynamo by paying {1} and tapping it, copying Tezzeret's ability, targeting Firemind Vessel and The Peregrine Dynamo.
Resolve the copy of Tezzeret's ability, untapping Firemind Vessel and The Peregrine Dynamo.
Repeat from step 2.

Tezzeret the Seeker

The Peregrine Dynamo

Activate Trazyn using Firemind Vessel's ability by tapping it, adding {U} and one mana of another color.
Activate Trazyn using Soliton's ability by paying {U}, untapping it.
Repeat.

Combos with "Firemind Vessel"