Activate Carrion Howler by paying 1 life.
Vilis triggers, causing you to draw a card.
Sheoldred's first ability triggers, causing you to gain 2 life.
Repeat as desired.
Resolve all Carrion Howler abilities.

Infinite card draw

Infinite draw triggers

Near-infinite lifegain

Near-infinite lifegain triggers

Sheoldred, the Apocalypse

Vilis, Broker of Blood

Carrion Howler

Activate Vizkopa Guildmage by paying {1}{W}{B}, causing each opponent to lose life whenever you gain life this turn.
Activate Carrion Howler by paying 1 life.
Repeat step 2 until you have one life.
Resolve all Carrion Howler abilities, giving itself +2/-1 for each ability.
Cast Oketra's Last Mercy by paying {1}{W}{W}, causing your life total to become forty.
Vizkopa Guildmage triggers, causing each opponent to lose thirty-nine life.
Each opponent loses the game due to having zero or less life.

Each opponent loses the game

Vizkopa Guildmage

Oketra's Last Mercy

Combos with "Carrion Howler"