Activate Ashnod's Altar by sacrificing Priest of Urabrask, adding {C}{C}.
When Priest of Urabrask dies, Mortuary triggers, putting Priest of Urabrask on top of your library from your graveyard.
Actviate Impromptu Raid by paying {2}{R/G}, revealing Priest of Urabrask from the top of your library and putting it onto the battlefield.
When Priest of Urabrask enters the battlefield, it triggers, adding {R}{R}{R}.
Repeat.

Infinite colorless mana

Infinite death triggers

Infinite creature ETB

Infinite creature LTB

Infinite red mana

Infinite creature sacrifice triggers

Impromptu Raid

Mortuary

Ashnod's Altar

Priest of Urabrask

Activate Ashnod's Altar by sacrificing Burning-Tree Emissary, adding {C}{C}.
When Burning-Tree Emissary dies, Mortuary triggers, putting Burning-Tree Emissary on top of your library from your graveyard.
Actviate Impromptu Raid by paying {2}{R/G}, revealing Burning-Tree Emissary from the top of your library and putting it onto the battlefield.
When Burning-Tree Emissary enters the battlefield, it triggers, adding {R}{G}.
Repeat.

Infinite green mana

Burning-Tree Emissary

Activate Phyrexian Altar by sacrificing Priest of Urabrask, adding {R/G}.
When Priest of Urabrask dies, Mortuary triggers, putting Priest of Urabrask on top of your library from your graveyard.
Actviate Impromptu Raid by paying {2}{R/G}, revealing Priest of Urabrask from the top of your library and putting it onto the battlefield.
When Priest of Urabrask enters the battlefield, it triggers, adding {R}{R}{R}.
Repeat.

Infinite colored mana

Phyrexian Altar

Activate Phyrexian Altar by sacrificing Burning-Tree Emissary, adding {R/G}.
When Burning-Tree Emissary dies, Mortuary triggers, putting Burning-Tree Emissary on top of your library from your graveyard.
Actviate Impromptu Raid by paying {2}{R/G}, revealing Burning-Tree Emissary from the top of your library and putting it onto the battlefield.
When Burning-Tree Emissary enters the battlefield, it triggers, adding {R}{G}.
Repeat.

Activate Thermopod's second ability by sacrificing Arashin Sovereign, adding {R}.
When Arashin Sovereign dies, it triggers, putting itself on top of your library from your graveyard.
Activate Impromptu Raid by paying {R/G}, revealing Arashin Sovereign from the top of your library and putting it onto the battlefield.
Repeat.

Arashin Sovereign

Zirda, the Dawnwaker

Thermopod

Activate Phyrexian Altar by sacrificing Arashin Sovereign, adding {R/G}.
When Arashin Sovereign dies, it triggers, putting itself on top of your library from your graveyard.
Activate Impromptu Raid by paying {R/G}, revealing Arashin Sovereign from the top of your library and putting it onto the battlefield.
Repeat.

Activate Thermopod's second ability by sacrificing Golgari Thug, adding {R}.
When Golgari Thug dies, it triggers, putting itself on top of your library from your graveyard.
Activate Impromptu Raid by paying {R/G}, revealing Golgari Thug from the top of your library and putting it onto the battlefield.
Repeat.

Golgari Thug

Activate Phyrexian Altar by sacrificing Golgari Thug, adding {R/G}.
When Golgari Thug dies, it triggers, putting itself on top of your library from your graveyard.
Activate Impromptu Raid by paying {R/G}, revealing Golgari Thug from the top of your library and putting it onto the battlefield.
Repeat.

Combos with "Impromptu Raid"