Sift Combos
Nether Traitor + Sifter of Skulls + Pitiless Plunderer
Yawgmoth, Thran Physician + Sifter of Skulls + Zulaport Cutthroat
Combo result
Draw your library. Life drain for each opponent, limited by cards in your library. (Not Infinite life loss for opponents). Many -1/-1 counters placed on target creature/s, limited by half the cards in your library. Infinite ETB. Infinite death triggers. Infinite LTB.
Prerequisites
All permanents on the battlefield. More cards in library than each opponent's life total.
Wild Pair + Horned Kavu + Sifter of Skulls
Whisper, Blood Liturgist + Thornbite Staff + Sifter of Skulls
Wavesifter + Academy Manufactor + Temur Sabertooth
Varragoth, Bloodsky Sire + Timesifter + Emiel the Blessed
Timesifter + Draco + Isochron Scepter
The Balrog, Durin's Bane + Phyrexian Altar + Sifter of Skulls
Combo result
Infinite ETB. Infinite LTB. Infinite death triggers. Infinite sacrifice triggers. Infinite storm count. Infinite commander casts.
Prerequisites
The Balrog in the command zone. All other permanents on the battlefield. There have been a number of permanents sacrificed this turn equal to five plus The Balrog's commander tax. {B}{R} available.