msem-instigator

When Eaveshoppers enters, each opponent discards a card.
Inspired — Whenever Eaveshoppers becomes untapped, exile up to one target card from a graveyard. If a land card is exiled this way, put a +1/+1 counter on Eaveshoppers.

When Peeto enters, scry 2.
Whenever a Scout you control attacks, choose land or nonland, then look at the top card of your library. If it's a card of the chosen kind, you may reveal it and draw a card.

Pyre Trap deals 2 damage to any target.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Pyre Trap deals 4 damage instead, and you may cast it as though it had flash.

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.)
At the beginning of each player's upkeep, they sacrifice a nonenchantment creature. Then if there are no nonenchantment creatures on the battlefield, sacrifice Kantra of Plagues.

Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles.
Scry 1.

Target opponent reveals their hand. Choose a nonland card revealed this way. That player discards that card.
You lose 2 life and create a 2/1 black Spirit creature token with “This creature can't block.”

{T}: Add one mana of any color. If you spend this mana to cast a face-down creature spell, you gain 2 life.

Swarming Midden enters tapped unless you control a basic Swamp.
{T}: Add {B}.
{1}{B}{B}: Swarming Midden becomes a 2/3 black Rat creature with menace until end of turn. It's still a land. Whenever it attacks this turn, create a 1/1 black Rat creature token with “This creature can't block.”

Vigilance (Attacking doesn't cause this creature to tap.)

Equipped creature gets +2/+0 and has “{T}, Unattach Javelin: It deals 2 damage to target creature.”
Equip {2}

Nimblefoot can't be blocked.

When Grisly Reaper enters, you may exile a creature card from your graveyard. When you do, create a 1/1 black Skeleton creature token.

[+1]: Each opponent discards a card. If a land card is discarded this way, create a 1/1 colorless Spirit creature token with flying.
[–2]: Until end of turn, creatures you control get +1/+1 and creatures your opponents control get -1/-1.
[–6]: Each opponent chooses up to one permanent they control of each permanent type, then sacrifices the rest.

Destroy target artifact or enchantment. Its controller gains 4 life.

Enchant creature you control
Whenever a land you control enters, put a +1/+1 counter on enchanted creature.
{3}{G}, Sacrifice Trace the Oasis: Draw cards equal to enchanted creature's power.

Thornwood Falls enters tapped.
When Thornwood Falls enters, you gain 1 life.
{T}: Add {G} or {U}.

Menace, ward {2}
Whenever Envoy of Divine Progress deals combat damage to a player, you may search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Whenever you draw a card, put a quest counter on Seek Perfection.
At the beginning of each end step, if Seek Perfection has four or more quest counters on it, exile target permanent you control, then return it to the battlefield under your control.

Target player draws a card. Put target spell or nonland permanent that player controls on top of its owner's library.

Flying, trample, haste
Whenever you activate an ability of a nonland permanent, you may have Ilieth, Transcendent deal 2 damage to target creature.
{2}{R}: Creatures you control get +2/+0 until end of turn.

As an additional cost to cast this spell, sacrifice a creature.
Enchant creature
Enchanted creature gets +4/+4, has flying, and is a Demon in addition to its other types.

Equipped creature gets +1/+1.
Whenever equipped creature becomes the target of a spell or ability an opponent controls, you may return Shawl of Warding to its owner's hand. If you do, counter that spell or ability.
Equip {2}

Whenever you sacrifice a permanent, you may put a -1/-1 counter on target creature.

Flash
Prowess
When Ella enters, create two 1/1 blue Wizard creature tokens with prowess.
Whenever you cast a noncreature spell, you may sacrifice a creature. If you do, copy that spell. You may choose new targets for the copy.

[+1]: Scry 3.
[–2]: Choose a card name, then mill a card. If that card has the chosen name, you draw three cards. Otherwise, you draw a card.
[–6]: You get an emblem with “Play with the top card of your library revealed” and “You may play the top card of your library.”