Sydri, Galvanic Genius

{U}: Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn.
{W}{B}: Target artifact creature gains deathtouch and lifelink until end of turn.

Yennett, Cryptic Sovereign

Flying, vigilance, menace
Whenever Yennett attacks, reveal the top card of your library. You may cast it without paying its mana cost if its mana value is odd. If you don't cast it, draw a card.

Eriette, the Beguiler

Lifelink
Whenever an Aura you control becomes attached to a nonland permanent an opponent controls with mana value less than or equal to that Aura's mana value, gain control of that permanent for as long as that Aura is attached to it.

The Master of Keys

Flying
When The Master of Keys enters, put X +1/+1 counters on it and mill twice X cards.
Each enchantment card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)

Saruman of Many Colors

Ward—Discard an enchantment, instant, or sorcery card.
Whenever you cast your second spell each turn, each opponent mills two cards. When one or more cards are milled this way, exile target enchantment, instant, or sorcery card with equal or lesser mana value than that spell from an opponent's graveyard. Copy the exiled card. You may cast the copy without paying its mana cost.

Varina, Lich Queen

Whenever you attack with one or more Zombies, draw that many cards, then discard that many cards. You gain that much life.
{2}, Exile two cards from your graveyard: Create a tapped 2/2 black Zombie creature token.

Raffine, Scheming Seer

Flying, ward {1}
Whenever you attack, target attacking creature connives X, where X is the number of attacking creatures. (Draw X cards, then discard X cards. Put a +1/+1 counter on that creature for each nonland card discarded this way.)

Dakkon Blackblade

Dakkon Blackblade's power and toughness are each equal to the number of lands you control.