Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Swamp

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.