Have

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Demonic Tutor

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

Brain Pry

Choose a nonland card name. Target player reveals their hand. That player discards a card with that name. If they can't, you draw a card.

Sign in Blood

Target player draws two cards and loses 2 life.

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Imperial Seal

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

Mox Jet

Black Lotus

{T}, Sacrifice Black Lotus: Add three mana of any one color.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Dark Ritual

Vampiric Tutor

Putrid Goblin

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Swamp

Thran Vigil

Whenever one or more artifact and/or creature cards leave your graveyard during your turn, put a +1/+1 counter on target creature you control.