msem-instigator

As an additional cost to cast this spell, sacrifice a creature.
Put X +1/+1 counters on target creature you control, where X is the sacrificed creature's power. You gain X life.

Flash
Flying
Sacrifice Vengeful Messenger: Counter target noncreature spell unless its controller pays {2}.

Deathtouch
Menagerie — When Venomfrill Familiar enters the battlefield, if there are five or more creature types among creatures you control, you may destroy target creature or planeswalker.

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)
Whenever Venomous Haploc becomes blocked, other creatures you control gain deathtouch until end of turn.

You may play an additional land on each of your turns.
Whenever a land enters the battlefield under your control, creatures you control get +1/+1 until end of turn.

Reveal the top thirteen cards of your library. For each permanent type, you may put a card of that type revealed this way into your hand. Put the rest into your graveyard. (The permanent types are creature, land, artifact, enchantment and planeswalker.)

When Verdict of the Council enters the battlefield, exile up to one target creature until Verdict of the Council leaves the battlefield.
White creatures you control get +1/+0.

Menace

Whenever one or more other nontoken creatures die, create a Food token. (It's an artifact with “{2}, {T}, Sacrifice this artifact: You gain 3 life.”)
Whenever you sacrifice a Food, create a 1/1 black Bat creature token with flying.

Flying
{2}{B}, Sacrifice another creature: Target creature gets -3/-3 until end of turn.

All creatures get -X/-X until end of turn. X can't be 0.
Whenever a creature dies this turn, create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

When Victims of Graygulch enters the battlefield, target player loses life equal to the number of Spirits you control. You gain life equal to the life lost this way.

Haste
When Vidal enters the battlefield, reveal cards from the top of your library until you reveal an enchantment card with mana value 3 or less. Put that card onto the battlefield and the rest on the bottom of your library in a random order. Sacrifice that enchantment at the beginning of the next end step.

Vigilance
{6}: You may tap or untap target creature.

Vigorbreath Scourge enters the battlefield with X +1/+1 counters on it.
Whenever Vigorbreath Scourge attacks, it gets +X/+X until end of turn, where X is your devotion to green. Then if its power is 6 or greater, draw a card. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

[+1]: Each player discards a card or sacrifices a creature.
[–3]: Vikalden deals X damage to any target and you gain X life, where X is the number of Swamps you control.
[–5]: You get an emblem with “{B}, Pay 2 life: Draw a card.”

Whenever one or more creatures die for the first time each turn, you draw a card and you lose 1 life.
Whenever you cast a black noncreature spell, Villainy deals 2 damage to any target and you gain 2 life.

Tithe (When this creature enters the battlefield, you may tap three other artifacts and/or creatures you control.)
When Vindictive Abbot enters the battlefield, you may have target creature get -1/-1 until end of turn. If Vindictive Abbot's tithe was paid, destroy that creature.

All creatures get -3/-3 until end of turn.

Destroy target creature or planeswalker. Each player loses life equal to that permanent's mana value.

This spell costs {1} less to cast for each creature that attacked this turn.
Violent Offensive deals 4 damage to any target.

Flying
At the beginning of your end step, if you gained 4 or more life this turn, create a 4/4 white Angel creature token with flying.

Once each turn, you may activate an additional loyalty ability of a planeswalker you control.
[+1]: You gain 1 life for each loyalty ability you've activated this turn. Scry 1.
[0]: Put a +1/+1 counter on target creature. It can't attack or block until your next turn.
[–3]: Exile target creature with power 4 or greater.

Target player draws X cards and loses X life.

Archive 13 (As this enters the battlefield, shuffle the top thirteen cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
At the beginning of your upkeep, you lose half your life, rounded up, and you draw half of the cards from the archived library, rounded up.