Nightmare's Thirst

You gain 1 life. Target creature gets -X/-X until end of turn, where X is the amount of life you gained this turn.

Souldrinker

Pay 3 life: Put a +1/+1 counter on Souldrinker.

Braidwood Cup

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Chalice of Death

Chalice of Life

{T}: You gain 1 life. Then if you have at least 10 life more than your starting life total, transform Chalice of Life.

Chalice of Life // Chalice of Death

Belbe, Corrupted Observer

At the beginning of each player's postcombat main phase, that player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)

Cankerous Thirst

If {B} was spent to cast this spell, you may have target creature get -3/-3 until end of turn. If {G} was spent to cast this spell, you may have target creature get +3/+3 until end of turn. (Do both if {B}{G} was spent.)

Sip of Hemlock

Destroy target creature. Its controller loses 2 life.

Marshdrinker Giant

When Marshdrinker Giant enters the battlefield, destroy target Island or Swamp an opponent controls.

Hierophant's Chalice

When Hierophant's Chalice enters the battlefield, target opponent loses 1 life and you gain 1 life.
{T}: Add {C}.

Poison the Cup

Destroy target creature. If this spell was foretold, scry 2.
Foretell {1}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Bloodchief's Thirst

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Destroy target creature or planeswalker with mana value 2 or less. If this spell was kicked, instead destroy target creature or planeswalker.

Healing Leaves

Choose one —
• Target player gains 3 life.
• Prevent the next 3 damage that would be dealt to any target this turn.