Cast Leshrac's Sigil by paying 4 life, enabled by K'rrik's ability.
When you cast Leshrac's Sigil, each creature you control's extort ability from Pontiff of Blight triggers.
Resolve an extort trigger by paying 2 life as enabled by K'rrik, causing each opponent to lose 1 life and gaining 3 life.
Resolve seven additional extort triggers, netting 7 additional life.
Activate Leshrac's Sigil's last ability by paying 4 life, returning it from the battlefield to your hand.
Repeat.

Near-infinite lifegain triggers

Infinite lifeloss

K'rrik, Son of Yawgmoth

Leshrac's Sigil

Pontiff of Blight

Activate Viscera Seer by sacrificing Gravecrawler, causing you to scry 1.
Cast Gravecrawler from your graveyard by paying {B} or 2 life due to K'rrik.
K'rrik triggers, as well as each creature you control's extort ability.
Resolve the first K'rrik trigger, putting a +1/+1 counter on it.
Resolve the first extort trigger, causing you to pay {W/B} or 2 life due to K'rrik, causing each opponent to lose 1 life and you to gain that much life.
Repeat step 5 for each remaining trigger.
Repeat from step 1.

Infinite +1/+1 counters on a creature

Infinite death triggers

Infinite creature ETB

Infinite lifegain

Infinite lifegain triggers

Infinite creature LTB

Infinite creature sacrifice triggers

Infinite scry 1

Infinite storm count

Gravecrawler

Viscera Seer

Activate Carrion Feeder by sacrificing Gravecrawler, putting a +1/+1 counter on Carrion Feeder.
Cast Gravecrawler from your graveyard by paying {B} or 2 life due to K'rrik.
K'rrik triggers, as well as each creature you control's extort ability.
Resolve the first K'rrik trigger, putting a +1/+1 counter on it.
Resolve the first extort trigger, causing you to pay {W/B} or 2 life due to K'rrik, causing each opponent to lose 1 life and you to gain that much life.
Repeat step 5 for each remaining trigger.
Repeat from step 1.

Infinite +1/+1 counters on most creatures you control

Carrion Feeder

Activate Ashnod's Altar by sacrificing Gravecrawler, adding {C}{C}.
Cast Gravecrawler from your graveyard by paying {B} or 2 life due to K'rrik.
K'rrik triggers, as well as each creature you control's extort ability.
Resolve the first K'rrik trigger, putting a +1/+1 counter on it.
Resolve the first extort trigger, causing you to pay {W/B} or 2 life due to K'rrik, causing each opponent to lose 1 life and you to gain that much life.
Repeat step 5 for each remaining trigger.
Repeat from step 1.

Infinite colorless mana

Ashnod's Altar

Activate Altar of Dementia by sacrificing Gravecrawler, causing target player to mill cards equal to its power.
Cast Gravecrawler from your graveyard by paying {B} or 2 life due to K'rrik.
K'rrik triggers, as well as each creature you control's extort ability.
Resolve the first K'rrik trigger, putting a +1/+1 counter on it.
Resolve the first extort trigger, causing you to pay {W/B} or 2 life due to K'rrik, causing each opponent to lose 1 life and you to gain that much life.
Repeat step 5 for each remaining trigger.
Repeat from step 1.

Infinite mill

Infinite self-mill

Altar of Dementia

Cast Mourning by paying 2 life if able, or {B} otherwise.
Each creature you control's extort ability triggers.
Resolve the first extort trigger, causing you to pay 2 life if able, or {W/B} otherwise, causing each opponent to lose 1 life and you to gain that much life.
Repeat step 3 for each remaining extort trigger.
Resolve Mourning, attaching it to a creature you control.
Activate Mourning by paying 2 life, returning it from the battlefield to your hand.
Repeat until an opponent loses the game due to having 0 or less life.

Combos with "Pontiff of Blight"