Sengir Nosferatu

Flying
{1}{B}, Exile this creature: Create a 1/2 black Bat creature token with flying. It has "{1}{B}, Sacrifice this token: Return an exiled card named Sengir Nosferatu to the battlefield under its owner's control."

Skittering Monstrosity

When you cast a creature spell, sacrifice this creature.

Divine Congregation

You gain 2 life for each creature target player controls.
Suspend 5—{1}{W} (Rather than cast this card from your hand, you may pay {1}{W} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Skulking Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
When this creature becomes the target of a spell or ability, sacrifice it.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Strangling Soot

Destroy target creature with toughness 3 or less.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Stronghold Overseer

Flying
Shadow (This creature can block or be blocked by only creatures with shadow.)
{B}{B}: Creatures with shadow get +1/+0 until end of turn and creatures without shadow get -1/-0 until end of turn.

Sudden Death

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Target creature gets -4/-4 until end of turn.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Traitor's Clutch

Target creature gets +1/+0, becomes black, and gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Trespasser il-Vec

Discard a card: This creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Urborg Syphon-Mage

{2}{B}, {T}, Discard a card: Each other player loses 2 life. You gain life equal to the life lost this way.

Duskrider Peregrine

Flying, protection from black
Suspend 3—{1}{W} (Rather than cast this card from your hand, you may pay {1}{W} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Vampiric Sliver

All Sliver creatures have "Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature."

Viscid Lemures

{0}: This creature gets -1/-0 and gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Time Spiral