Profane Transfusion

Two target players exchange life totals. You create an X/X colorless Horror artifact creature token, where X is the difference between those players' life totals.

Tainted Remedy

If an opponent would gain life, that player loses that much life instead.

Soul Conduit

{6}, {T}: Two target players exchange life totals.

False Cure

Until end of turn, whenever a player gains life, that player loses 2 life for each 1 life they gained.

Plague Drone

Flying
Rot Fly — If an opponent would gain life, that player loses that much life instead.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Blessed Wind

Axis of Mortality

At the beginning of your upkeep, you may have two target players exchange life totals.