Activate Phyrexian Altar by sacrificing Nether Traitor, adding {B}.
When Nether Traitor dies, Field of Souls triggers, creating a creature token.
Activate Phyrexian Altar by sacrificing the creature token, adding one mana of any color.
When the creature token dies, Nether Traitor triggers, causing you to pay {B} to return Nether Traitor from your graveyard to the battlefield.
Repeat.

Infinite LTB

Infinite ETB

Infinite colored mana

Infinite sacrifice triggers

Infinite death triggers

Nether Traitor

Phyrexian Altar

Field of Souls

Activate Phyrexian Altar by sacrificing Oathsworn Vampire, adding {B}.
When Oathsworn Vampire dies, Field of Souls triggers, creating a creature token.
Activate Phyrexian Altar by sacrificing the creature token, adding {1}.
Cast Oathsworn Vampire from your graveyard by paying {1}{B}.
Repeat.

Infinite storm count

Oathsworn Vampire

Activate Phyrexian Altar by sacrificing Ozox, adding {1}.
When Ozox dies, it and Field of Souls trigger.
Resolve the Ozox trigger, creating a legendary 2/1 Jumblebones creature token.
Resolve the Field of Souls trigger, creating a creature token.
Activate Phyrexian Altar twice by sacrificing Jumblebones and the other creature token, adding {1}{B}.
When Jumblebones dies, it triggers, returning Ozox from your graveyard to your hand.
Cast Ozox by paying {2}{B}.
Repeat.

Ozox, the Clattering King

Activate Ashnod's Altar by sacrificing Circle of the Land Druid, adding {C}{C}.
When Circle of the Land Druid dies, its second ability, Field of Souls and Pitiless Plunderer trigger.
Resolve the Field of Souls trigger, creating a creature token.
Resolve the Circle of the Land Druid trigger, returning Takenuma from your graveyard to your hand.
Resolve the Pitiless Plunderer trigger, creating a Treasure token.
Activate Ashnod's Altar by sacrificing the creature token, adding {C}{C}.
When the creature token dies, Pitiless Plunderer triggers, creating a Treasure token.
Activate the Treasures by tapping and sacrificing them, adding {B}{G}.
Activate Takenuma's channel ability by paying at most {3}{B}, returning Circle of the Land Druid from your graveyard to your hand.
Cast Circle of the Land Druid by paying {1}{G}.
When Circle of the Land Druid enters, its first ability triggers, allowing you to mill four cards.
Repeat.

Infinite self-mill

Infinite colorless mana

Infinite self-discard triggers

Circle of the Land Druid

Takenuma, Abandoned Mire

Pitiless Plunderer

Ashnod's Altar

Activate Thermopod by sacrificing Squee, adding {R}.
When Squee dies, Field of Souls triggers, creating a creature token.
Activate Thermopod by sacrificing the creature token, adding {R}.
Cast Squee from your graveyard by paying {R}{R} due to Green Goblin.
Repeat.

Norman Osborn // Green Goblin

Squee, the Immortal

Thermopod

Cast Ebondeath from your graveyard by paying {B}{B} due to Green Goblin.
Activate Phyrexian Altar by sacrificing Ebondeath, adding {B}.
When Ebondeath dies, Field of Souls triggers, creating a creature token.
Activate Phyrexian Altar by sacrificing the creature token, adding {B}.
Repeat.

Combos with "Field of Souls"