msem-instigator

Menace
Whenever Silver-Dawn Radiant becomes the target of a spell or ability you don't control, it deals damage equal to its power to that spell or ability's controller.

Enchant creature
Enchanted creature can't attack or block.

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Haste
Whenever you cast a creature spell, it gains bloodthirst 1. (Multiple instances of bloodthirst on a spell stack.)

Adjudicate, then Admonish the Unruly deals damage to target creature equal to the number of Auras you control. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)

{T}: Add {C}.
{1}: Hoof Cliff Horngrove becomes a 2/2 Elemental creature until end of turn. It's still a land.
Menagerie — Whenever Hoof Cliff Horngrove becomes a creature, it gains your choice of +1/+1, flying, first strike, lifelink, trample, or haste until end of turn. This ability triggers only if there are five or more creature types among creatures you control.

Enchant creature
Enchanted creature gets +1/+2.
Whenever enchanted creature attacks, scry 1.

As an additional cost to cast this spell, exile any number of cards from your graveyard. This spell costs {1} less to cast for each card exiled this way.
All creatures get -3/-3 until end of turn.

Well of Eternity enters with X charge counters on it.
At the beginning of your first main phase, choose a color, then add one mana of that color for each charge counter on Well of Eternity.

Defender, trample
Tap any number of other untapped creatures you control with total toughness 8 or greater: Formidable Bulkvine's base power becomes 8 until end of turn and it can attack this turn as though it didn't have defender.

[+1]: Create a 1/1 black Faerie creature token with flying and a 2/2 white Spirit Noble creature token with lifelink.
[–X]: Target creature gets -X/-X until end of turn. Its controller loses X life.
[–7]: You get an emblem with “Whenever a permanent you control enters, you may have it gain flying and vigilance and become a 4/4 Angel creature in addition to its other types.” (This effect lasts indefinitely.)

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)

Nonstoried creatures lose all abilities and have base power and toughness 1/1. (Enchantments and legendary permanents are storied.)

Foretell {2}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
If this spell is foretold, you may cast it as though it had flash.
Create a token that's a copy of target creature you control.

Enchant player
At the beginning of enchanted player's upkeep, if they control two or more creatures and/or planeswalkers, they sacrifice a creature or planeswalker.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets +2/+3 and has lifelink.

Flash
When Axom enters, remove up to three counters from target permanent.
{2}{U}: Return Axom to its owner's hand.

Whenever a creature you control enters for the second time each turn, you may put a +1/+1 counter on Warren Wardens.

Flying
When Tengu Skyguard enters, return a permanent you control to its owner's hand.

Flash
Vanishing 3 (This permanent enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Judge's Decree enters, exile another target spell or nonland permanent. When Judge's Decree is no longer on the battlefield, the exiled card's owner may cast that card without paying its mana cost.

Whenever one or more creatures you control deal combat damage to a player, you may destroy target artifact or enchantment that player controls.
Whenever you cast a green creature spell, create a 3/3 green Wurm creature token with trample.

Other Angels and Nephilim you control get +1/+0.
{3}{W}: Until end of turn, Hooded Mystic becomes an Angel, gets +3/+3 and gains flying.

Zygos, Underworld Scourge's power and toughness are each equal to the number of cards you own in exile and in your graveyard.
Spells you cast have “As an additional cost to cast this spell, you may exile any number of cards from your graveyard. This spell costs {1} less to cast for each card exiled this way.”

Soldiercycling {2}{W} ({2}{W}, Discard this card: Search your library for a Soldier card, reveal it, and put it into your hand, then shuffle.)

Equipped creature has first strike.
{R}: Equipped creature gets +1/+0 until end of turn.
Equip {2}

Flash
When Gilded Blade enters, you may attach it to target creature you control.
Equipped creature gets +1/+1.
Equip {1}