msem-instigator

Exile target creature, then return that card to the battlefield under its owners' control.

When Godwatcher enters, search any player's library for a creature card, exile it, then they shuffle their library.
When Godwatcher dies, put the exiled card onto the battlefield under your control.

({T}: Add {W}, {U}, or {B}.)
Coastal Dominion enters tapped.

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

Each opponent plays with the top card of their library revealed.
During each of your turns, you may play one card from the top of an opponents' library, and you may spend mana as though it were mana of any color to cast that spell.

I, II — Put a +1/+1 counter on target creature you control.
Discovery — Creatures you control with +1/+1 counters on them have lifelink.

Choose one—
• Return target creature to its owner's hand.
• Target creature gets +2/+0 and gains first strike until end of turn.
• Draw two cards, then discard a card at random.

At the beginning of your end step, if you've sacrificed three or more permanents this turn, return Demon of Necessary Evil from your graveyard to the battlefield.

When Limbhacker Blade enters, each opponent discards a card.
Equipped creature gets +2/+0.
Equip {2}

When Aureate Golem enters, create a Treasure token. Each other player creates a tapped Treasure token. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Enchant creature
Enchanted creature can't become untapped.
{4}{U}: Return Frozen Halo and enchanted creature to their owners' hands.

Enchant creature
Enchanted creature gets +2/+2 and has trample and indestructible.

When Vagabond of the Dunes enters, each opponent discards a card.
Whenever an opponent discards a card, put a +1/+1 counter on Vagabond of the Dunes.
Surpass {5}{B} ({5}{B}: Transform this creature. This costs {1} less to activate for each counter
on it. Activate only as a sorcery.)

Choose one —
• Look at the top five cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
• Destroy target creature with flying.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Leotau Rider encourages a creature, that creature gains trample until end of turn.

Whenever Bold Vanquisher attacks, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Trample

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

When Unburdening Priest enters, you may exile any number of creatures you control not named Unburdening Priest, then return those cards to the battlefield under your control.

[progress 2+]
[progress 5+]
Whenever a creature enters, each opponent loses 1 life.

If you would gain life, you gain twice that much life instead.
If you would draw a card, draw two cards instead.
If you tap a permanent for mana, it produces twice as much of that mana instead.

Choose one —
• When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn

Target creature you control gets +X/+0 until end of turn. It deals damage equal to its power to up to one target creature.

Primal {2}{R} (During your turn, you may cast this spell for {2}{R} instead of playing a land.)
Target creature gets +2/+0 and gains double strike until end of turn.

When Humble Archivist enters, you may return target instant or sorcery card from your graveyard to your hand. If you do, conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

As an additional cost to cast this spell, sacrifice a creature.
Search your library for up to X cards and put them into your hand, where X is the sacrificed creature's power, then shuffle.