The Beast, Deathless Prince

When you cast this spell, gain control of target creature until end of turn. Untap it. It gains menace and haste until end of turn.
The Beast enters the battlefield tapped with six stun counters on it. (If it would become untapped, remove a stun counter from it instead.)
Whenever a creature deals combat damage to its owner, untap The Beast and draw a card.

Olivia Voldaren

Flying
{1}{R}: Olivia Voldaren deals 1 damage to another target creature. That creature becomes a Vampire in addition to its other types. Put a +1/+1 counter on Olivia Voldaren.
{3}{B}{B}: Gain control of target Vampire for as long as you control Olivia Voldaren.

Conquering Manticore

Flying
When Conquering Manticore enters the battlefield, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Sauron, the Lidless Eye

When Sauron, the Lidless Eye enters the battlefield, gain control of target creature an opponent controls until end of turn. Untap it. It gains haste until end of turn.
{1}{B}{R}: Creatures you control get +2/+0 until end of turn. Each opponent loses 2 life.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Tevesh Szat, Doom of Fools

+2: Create two 0/1 black Thrull creature tokens.
+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.
−10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.
Tevesh Szat, Doom of Fools can be your commander.
Partner

Vampire Hexmage

First strike
Sacrifice Vampire Hexmage: Remove all counters from target permanent.

Lorcan, Warlock Collector

Flying
Whenever a creature card is put into an opponent's graveyard from anywhere, you may pay life equal to its mana value. If you do, put it onto the battlefield under your control. It's a Warlock in addition to its other types.
If a Warlock you control would die, exile it instead.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

Yawgmoth, Thran Physician

Protection from Humans
Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.
{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.