Garna, the Bloodflame | Priest of Gix | Priest of Urabrask

(and one other card)

Ashnod's Altar on the battlefield.
Garna in hand or in the command zone.
Priest of Gix and
Priest of Urabrask in hand.
({2} magic symbol) ({B} magic symbol) ({R} magic symbol) plus enough mana to pay for commander tax, if applicable available.

Cast
Priest of Gix by paying ({2} magic symbol) ({B} magic symbol) .
When
Priest of Gix enters the battlefield, it triggers, adding ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) .
Activate
Ashnod's Altar by sacrificing
Priest of Gix, adding ({C} magic symbol) ({C} magic symbol) .
Cast
Priest of Urabrask by paying ({2} magic symbol) ({R} magic symbol) .
When
Priest of Urabrask enters the battlefield, it triggers, adding ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Activate
Ashnod's Altar by sacrificing
Priest of Urabrask, adding ({C} magic symbol) ({C} magic symbol) .
Cast
Garna either from your hand or from the command zone by paying ({3} magic symbol) ({B} magic symbol) ({R} magic symbol) and commander tax, if applicable.
When
Garna enters the battlefield, it triggers.
Holding priority, activate
Ashnod's Altar by sacrificing
Garna, adding ({C} magic symbol) ({C} magic symbol) .
Resolve the
Garna trigger, returning it,
Priest of Gix and
Priest of Urabrask from your graveyard to your hand.
Repeat.