msem-instigator

Equipped creature gets +1/+3.
Whenever another creature blocks or becomes blocked by equipped creature, that creature loses all abilities until end of turn.
Equip {3}

Vigorbreath Scourge enters 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.)

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Vigilance

Target player sacrifices a creature.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

When Vile Weavers enters, if you control an enchantment, target player loses 3 life.

When Village Courier enters, look at the top four cards of your library. You may reveal an artifact, enchantment, or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Rhapsody {3}{R}{R} (Pay {3}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Whenever Vindictive Guardian or another creature you control enters, if that creature's power is 4 or greater, create a Treasure token.

Whenever Vindictive Pyromancer perseveres, it deals 1 damage to any other target. (A creature perseveres when it survives damage.)

Destroy target nontoken artifact. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

As an additional cost to cast this spell, sacrifice an artifact or creature.
Create three 1/1 red Construct creature tokens.

Reverberate {3}{U} (When you cast this spell, copy it if you paid its reverberate cost.)
If Violent Spasm is reverberated, creatures you control gain flying until end of turn. Violent Spasm deals 1 damage to each creature without flying.

{2}, {T}, Sacrifice Virtual Terrain: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Draw two cards, then discard two cards.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Target creature you control deals damage equal to its power to target creature you don't control.

Target player draws X cards and loses X life.

Enchant creature
Enchanted creature blocks each combat if able.
Whenever enchanted creature attacks, it loses flying until end of turn.

{T}: Add {G}.
{T}: Sacrifice Visionary Developer: Create a token that's a copy of target token you control. Activate only as a sorcery.

At the beginning of your upkeep, look at the top card of your library. If it's an artifact card, you may reveal it and put it into your hand.

Lifelink
Vitality of Blossoms has indestructible as long as your life total is greater than your starting life total.

Whenever you sacrifice a Clue, Vivian's Vanguard gets +2/+0 and gains flying until end of turn.

Whenever you cast your second spell each turn, create a 1/1 blue Jellyfish Spirit creature token with flying.

This spell costs {2} more to cast for each target beyond the first.
Choose one or more —
• Counter target activated or triggered ability from a nonland source.
• Vivien's Endeavor deals 6 damage to target attacking creature with flying.
• Target player searches their library for a creature card with colossal, reach, trample, or vigilance, reveals it, puts it into their hand, then shuffles.

Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters.)
{2}{B}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Noncreature spells you cast cost {1} less to cast. This effect can't reduce the amount of mana a spell costs to cast to less than one mana.

Sacrifice Voice of Ambition: Target creature gets +2/+1 until end of turn.