msem-instigator

{T}: Add {C}.
{T}, Reappropriate: Add {R} or {W}. (Exile exactly two cards from your hand and/or graveyard.)

Flash
{1}, {T}: Scry 1.

Instant, sorcery, and enchantment spells you cast cost {1} less to cast.

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Croakfolk Marsh-Baron enters with X +1/+1 counters on it. If its tithe was paid, it enters with twice X +1/+1 counters instead.

Tap up to two target creatures.
Permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Target creature gets -9/-0 until end of turn. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)

{T}, Pay 1 life: Add {U} or {R}.
{1}, {T}, Sacrifice Heist Headquarters: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Trample, haste
When Weak-Spot Colossus is dealt exactly 1 damage, destroy it.

As Nebula of Empty Gold enters, choose two or three colors. You lose life equal to the number of colors chosen this way.
{T}: Add one mana of any of the chosen colors.

You draw two cards and you lose 2 life.
Amass Soldiers 2. (Put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

First strike
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Counter target spell.
Surveil 1.

Whenever a creature dies, exile it.
Hiroto Jaakuna has all activated abilities of creature cards exiled with Hiroto Jaakuna.

Search your library for a planeswalker card, exile it with two loyalty counters on it, then shuffle. If that card has mana value 4 or less, you may activate one of its loyalty abilities. Then put that card into your hand.

Destroy target noncreature, nonland permanent. (Destroying a battle doesn't remove counters from it.)
Flashback {3}{W}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

When Customs Lookout enters, each player draws a card, then discards a card.
Whenever an opponent casts a spell with the same name as a card they own in exile or in their graveyard, you may scry 2.

Fortress Arena enters tapped.
{T}: Add {R} or {W}.
{2}{R}{W}, {T}, Sacrifice Fortress Arena: Draw a card.

Whenever you cast a noncreature spell, look at the top X cards of your library, where X is that spell's mana value. Put those cards on top of your library in any order.

Haste
Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Spend only mana produced by artifacts to cast Dawson's Jetslicer.

When Herald of Darkness enters, destroy up to one target creature with mana value 3 or less.

Enchant creature
Enchanted creature gets +0/+2 and has “{T}: Draw a card.”

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if you've cast a noncreature spell this turn.

{T}: Add {C}.
Civilized — {T}: Add {C}{C}. Activate only if you control an artifact, a creature, and an enchantment.

({T}: Add {G} or {U}.)
Soaring Rainforest enters tapped.
{1}, {T}: Add {G}{G} or {U}{U}.