msem-instigator

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
Zoulev Envoy can't be blocked.

When Anointed General enters, if you control a legendary creature, Anointed General deals 4 damage to target creature you don't control.

Flying
When Owl of the Seven Stars enters, scry 2.

As New Divide enters, you may pay 2 life. If you don't, it enters tapped.
{T}, Sacrifice New Divide: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Whenever Glorybound Chorister attacks, put a +1/+1 counter on each other attacking creature you control.

Trample
When Remnant of the Wild enters, if you cast it, untap all lands you control.

(As an Encounter enters, choose an opponent to protect it while you and other players attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Crisis in Avaz enters, search your library for a basic land or Satrapy card, put it onto the battlefield tapped, then shuffle.

Whenever another creature in Daoshi Spiritdancer's pack dies, you may sacrifice Daoshi Spiritdancer. If you do, return that creature card to the battlefield under your control at the beginning of the next end step. (Two or more creatures you control with equal power are in a pack.)

Flying
When Carrion Drake enters, you may exile a creature card from your graveyard. If you do, draw a card.

When Demented Brainiac enters and at the beginning of your upkeep, each opponent mills two cards.
{U}, Sacrifice Demented Brainiac: Exile each opponent's graveyard. Until end of turn, you may cast instant and sorcery spells exiled this way, and you may spend mana as though it were mana of any color to cast them.

Soli Temple enters tapped.
Satrapies you control have “{T}: Add {G} or {W}.”

When Earthbreaker Behemoth enters, it deals damage equal to its power to up to one target creature you don't control. Excess damage is dealt to that creature's controller instead.

Flash
You may activate Zero's loyalty abilities any time you could cast an instant on your turn and the turn they entered.
[+2]: Destroy up to one target permanent with mana value 4 or greater.
[–2]: You may cast a spell with mana value 5 or less from your hand without paying its mana cost.
[–3]: Look at the top six cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

When Crescent of the Harvest Moon enters or whenever equipped creature attacks, exile up to one target card from a graveyard.
Equipped creature gets +1/+1.
{X}: Equipped creature becomes a copy of a permanent card with mana value X or less exiled with Crescent of the Harvest Moon until end of turn (even if this becomes unattached). Activate only as a sorcery.
Equip {2}

At the beginning of your upkeep, you may pay {1}{G}. If you do, create a 1/1 green Dryad creature token with “Sacrifice this creature: Add one mana of any color.”

When Fox of the Molten Dawn enters, you may return target Aura card with mana value 3 or less from your graveyard to the battlefield attached to a permanent it could enchant.

Creatures you control get +2/+0 until end of turn.

As an additional cost to cast this spell, you may discard two cards. If you do, this spell costs {3} less to cast and it can't be countered.
Exile the top three cards of your library. You may play those cards until the end of your next turn.

Flying
Whenever another creature you control enters from a graveyard or you revive a creature token, Tomb Scavenger gets +2/+0 until end of turn.

Vigilance, deathtouch, menace

When Pensive Muse enters, create a white Aura enchantment token named Seal's Love attached to target creature you control. The token has enchant creature and “Enchanted creatures you control get +1/+1.”

{T}: Add {R} or {W}. You lose 1 life unless you have less life than an opponent.

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
When Shoring Naiad enters, if {U} was spent to cast it, you may return an instant or sorcery card from your graveyard to your hand.