Activate Viscera Seer by sacrificing another creature.
When the creature dies, Teysa triggers, creating a 1/1 Spirit creature token that is black due to Darkest Hour.
Resolve the Viscera Seer ability.
Repeat.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Teysa, Orzhov Scion

Darkest Hour

Viscera Seer

All creatures are black.
Black creatures are unable to attack or block.

Players can't attack

Light of Day

Cast Elephant Grass by paying {G}.
Elephant Grass prevents creatures from attacking you due to Darkest Hour making them all black.
Solemnity prevents age counters from being placed on Elephant Grass.

Creatures cannot attack you

Elephant Grass

Solemnity

Whenever a creature enters the battlefield, Spreading Plague triggers, destroying all creatures, as they all black due to Darkest Hour.
Because Eldrazi Monument gives your creatures indestructible, only your opponents' creatures are destroyed.

Destroy all creatures opponents control whenever a creature enters the battlefield

Spreading Plague

Eldrazi Monument

Whenever a creature enters the battlefield, Spreading Plague triggers, destroying all creatures, as they all black due to Darkest Hour.
Because Avacyn gives your creatures indestructible, only your opponents' creatures are destroyed.

Avacyn, Angel of Hope

Cast Volcano Hellion by paying {2}{R}{R}.
Volcano Hellion enters the battlefield, dealing an arbitrarily large amount of damage to you and target creature, and causing you to gain life equal to the total amount of damage done this way.

Infinite lifegain

Volcano Hellion

Scion of Draco

Activate Ayara by tapping it and sacrificing another creature you control.
When the creature dies, Ayara triggers, untapping itself.
Resolve the Ayara ability from step 1, causing you to draw a card.
The Locust God triggers, creating a 1/1 Insect creature token with flying and haste.
Repeat.

Infinite card draw

Infinite draw triggers

Near-infinite death triggers

Near-infinite ETB

Near-infinite LTB

Near-infinite sacrifice triggers

Ayara, First of Locthwain

The Locust God

Thornbite Staff

Activate Ayara by tapping it and sacrificing another creature you control, causing you to draw a card.
The Locust God triggers, creating a 1/1 Insect creature token with flying and haste.
When the Insect enters the battlefield, Intruder Alarm triggers, untapping all creatures.
Repeat.

Combos with "Darkest Hour"