msem-instigator

Exile the top two cards of your library. Until the end of your next turn, you may play one of those cards, or both if this spell was foretold.
Foretell {R} (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.)

Flash
When Emissary of Dark Tides enters, you may return target noncreature spell or tapped creature to its owner's hand.

When Silt Miner enters, you may salvage an artifact or creature card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

When Trench Breaker enters, put target creature on top of its owner's library.

{T}: Add {C}.
{1}, {T}: Target player exiles a card from their graveyard. If a creature or planeswalker card is exiled this way, create a Vessel token. (It's an enchantment with “{2}, Sacrifice this enchantment: Create a 1/1 white Spirit creature token with flying.”)

First strike
Civilized — Whenever Palace Enforcer attacks, if you control an artifact, a creature, and an enchantment, Palace Enforcer gains deathtouch and lifelink until end of turn.

Return target creature to its owner's hand. You may shuffle up to four target cards from your graveyard into your library.

Defender
Venerable Loremaster can attack as though it didn't have defender if it's in a pack. (Two or more creatures you control with equal power are in a pack.)

{2}, {T}, Sacrifice Vial of Dragonfire: It deals 2 damage to target creature.

Enchant creature
You control enchanted creature.

Flash
Flying
When Seeker Amalgam enters, you may counter target spell with mana value less than or equal to the number of Elementals you control.

Whenever you make first contact, exile the top card of your library. You gain life equal to its mana value. You may play that card until the end of your next turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Menace
Whenever Margarete or another creature you control dies, up to one target creature you control cackles. (Put a menace counter on it. If it already has menace, it deals 1 damage to each opponent instead.)
Once each turn, when Margarete or another creature you control with menace dies, you may torment each opponent. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)

As Sunlit Highland enters, you may pay 2 life. If you don't, Sunlit Highland enters tapped.
{T}, Sacrifice Sunlit Highland: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Whenever you cast a spell with mana value greater than Script Jockey's power, put a +1/+1 counter on Script Jockey.

Flying, haste
Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
When Splitflame Phoenix dies, you may pay {R}. If you do, return it to its owner's hand.

Target player chooses a creature they control, then returns all other creatures they control to their owners' hands.

Copy target spell. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Create X 1/1 white Spirit creature tokens with flying, where X is two plus the number of cards named Wandering Souls in your graveyard. Conjure three cards named Wandering Souls and shuffle them into your main library.

First strike
When Majestic Monitor enters, if you control a legendary creature, creatures you control get +1/+0 and gain haste until end of turn.

Whenever one or more cards leave your graveyard for the first time each turn, each player loses 1 life and you draw a card.

{T}: Add {C}.
{T}, Pay 1 life: Add {R}.
{R}, {T}: Add one mana of any color.

Equipped creature gets +1/+0 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
Equip {2}

Whenever another creature named Reminiscing Youth you control enters, you may discard a card. If you do, draw a card.

Trample
Morph {3}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When you turn Spearhead Ophan face up, creatures you control get +2/+2 and gain trample until end of turn.