msem-instigator

[+1]: Until end of turn, whenever target creature deals combat damage to a player, that player mills two cards.
[–1]: Tap target creature. It can't become untapped for as long as you control Vaertris, Mindmelder.
[–6]: You get an emblem with “Whenever you draw a card, target player mills three cards” and “{2}{U}: Draw a card.”

Creatures you control have “Whenever this creature attacks, put a +1/+1 counter on target creature with lesser power.”
At the beginning of each end step, if there are five or more +1/+1 counters among creatures you control, destroy up to one target artifact or enchantment.

Deathwind Survivor's power and toughness are each equal to the number of enchantments you control.
Whenever an enchantment you control enters, put a +1/+1 counter on target creature.

Destroy target attacking or blocking creature.

This spell costs {1} less to cast if it targets a creature with power 3 or less.
Destroy target attacking or blocking creature.

When Oshiruko Purifier enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have lifelink.

Shu Qin enters with your choice of a flying or +1/+1 counter on him.
At the beginning of your upkeep, choose a creature in Shu Qin's pack. He gains that creature's abilities until end of turn. (Two or more creatures you control with equal power are in a pack.)

Mill three cards. You may return a card milled this way to your hand. Each opponent loses 2 life.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Kindle 2—{2}{G} ({2}{G}, Exile this card from your graveyard: Create two 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

At the beginning of your upkeep, create four 1/1 blue Elemental creature tokens with flying. You gain 4 life.
{2}{W}, Discard Olten's Farewell: Create two 1/1 blue Elemental creature tokens with flying. You gain 2 life.

Reach
Whenever one or more creatures with flying attack, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Harpstring Ranger gets +2/+2 until end of turn. Untap it.

({T}: Add {B}, {G}, or {U}.)
Verdant Dominion enters tapped.

Flying, menace

Flying
Whenever Rivha and at least two other creatures attack, exile all other attacking creatures you control. For each creature exiled this way, create a 3/3 white Angel creature token with flying that's tapped and attacking.

Whenever you cast a white spell, target player loses 2 life and you gain 2 life.
Whenever you cast a green spell, put a +1/+1 counter on Corrupted Warlord.

Menace
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

[+1]: Create a 1/1 blue Merfolk creature token with “When this creature dies, draw a card, then discard a card.”
[–1]: Target creature gets -2/-0 until your next upkeep and attacks during its controller's next turn if able.
[–7]: You get an emblem with “Creatures your opponents control get -4/-0 and attack each turn if able.”

Enchant creature
When Delegitimize enters, target opponent sacrifices a land.
Enchanted creature gets +2/+1.

Tears of Samang deals 3 damage to each creature and each player. If an opponent would be dealt damage this way, you may have Tears of Samang deal 3 damage to a planeswalker they control instead.

As an additional cost to cast this spell, pay {2} or sacrifice a creature.
Flying, vigilance

Whenever you activate a loyalty ability of a planeswalker, you gain 1 life.

Whenever an opponent casts a noncreature spell, create a Treasure token. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Flying
Whenever Seer of Clear Skies or another creature you control with flying attacks, that creature gets +1/+1 until end of turn.