Cast Peer into the Abyss by paying {4}{B}{B}{B}, causing you to draw half your library and lose half your life total, rounding up each time.
Activate Vizkopa Guildmage by paying {1}{W}{B}, causing each opponent to lose life whenever you gain life this turn.
Activate Martyr of Sands by paying {1}, revealing all white cards in your hand and sacrificing Martyr of Sands, causing you to gain 3 life for each card revealed this way.
Vizkopa Guildmage triggers, causing each opponent to lose life equal to the amount of life you gained.

Near-infinite lifegain

Near-infinite lifeloss

Combos with "Martyr of Sands"