Secret Lair Drop

Legendary Creature — Phyrexian Praetor

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Elesh Norn, Grand Cenobite

Enchantment

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Reconnaissance

Legendary Planeswalker — Jace

If you would draw a card while your library has no cards in it, you win the game instead.
+1: Target player mills two cards. Draw a card.
−8: Draw seven cards. Then if your library has no cards in it, you win the game.

Jace, Wielder of Mysteries

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Black Market

Whenever a blue creature you control enters, you may have target player draw a card.
Whenever a black creature you control enters, you may have target player discard a card.

Dire Undercurrents

Legendary Creature — Ogre Wizard

{T}: The player whose turn it is may end the turn. (Exile all spells and abilities from the stack. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Obeka, Brute Chronologist

Legendary Creature — Dragon Noble

Flying
Whenever Korvold enters or attacks, sacrifice another permanent.
Whenever you sacrifice a permanent, put a +1/+1 counter on Korvold and draw a card.