Prince of Thralls

Whenever a permanent an opponent controls is put into a graveyard, put that card onto the battlefield under your control unless that opponent pays 3 life.

Notion Rain

Surveil 2, then draw two cards. Notion Rain deals 2 damage to you. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Demon's Herald

{2}{B}, {T}, Sacrifice a blue creature, a black creature, and a red creature: Search your library for a card named Prince of Thralls, put it onto the battlefield, then shuffle.

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Dreamscape Artist

{2}{U}, {T}, Discard a card, Sacrifice a land: Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Diabolic Tutor

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

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.

Dizzy Spell

Target creature gets -3/-0 until end of turn.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Planar Bridge

{8}, {T}: Search your library for a permanent card, put it onto the battlefield, then shuffle.

Final Parting

Search your library for two cards. Put one into your hand and the other into your graveyard. Then shuffle.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Mastermind's Acquisition

Choose one —
• Search your library for a card, put it into your hand, then shuffle.
• Put a card you own from outside the game into your hand.

Marchesa, the Black Rose

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Other creatures you control have dethrone.
Whenever a creature you control with a +1/+1 counter on it dies, return that card to the battlefield under your control at the beginning of the next end step.

The Cauldron of Eternity

This spell costs {2} less to cast for each creature card in your graveyard.
Whenever a creature you control dies, put it on the bottom of its owner's library.
{2}{B}, {T}, Pay 2 life: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.