Ethereal Champion + Vizkopa Guildmage + Oketra's Last Mercy

Ethereal Champion

Vizkopa Guildmage

Oketra's Last Mercy

How it works

1. Activate Vizkopa Guildmage by paying 1, causing each opponent to lose life whenever you gain life this turn.
2. Activate Ethereal Champion by paying 1 life, preventing the next one damage dealt to it this turn.
3. Repeat step 2 until you have one life.
4. Cast Oketra's Last Mercy by paying 1, causing your life total to become forty.
5. Vizkopa Guildmage triggers, causing each opponent to lose thirty-nine life.
6. Each opponent loses the game due to having zero or less life.