msem-instigator

Choose one —
• Target creature gets -2/-2 until end of turn.
• Remove up to two counters from target permanent.

Deathtouch
Whenever Addermark Eviscerator deals combat damage to a player, draw a card.
At the beginning of your end step, if Addermark Eviscerator didn't attack this turn, transform it.

Flash
Return another artifact, creature, or enchantment you control to its owner's hand: Caylin Whirlwind gets +3/+3 until end of turn. Activate only once each turn.

Haste
Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)

{4}{G}, Discard a card: Reveal cards from the top of your library until you reveal a nonland permanent card. Put that card onto the battlefield and the rest into your graveyard.

Trample
As long as you control an Elemental creature, Wildheart Gorran gets +1/+1.

When United in Battle enters, look at the top six cards of your library. You may reveal a Dwarf or Elf card from among them and put it into your hand. Put the rest on the bottom in a random order.
Whenever a Dwarf or Elf you control enters, put a +1/+1 counter on it.

At the beginning of your end step, draw a card.
Whenever a creature deals combat damage to you, that creature's controller gains control of Ambition's Crown.

(As an Encounter enters, choose an opponent to protect it. You and others can 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 Dawn Over Danaj enters or is defeated, draw cards equal to the greatest power among creatures you control.

Protection from multicolored
[+2]: Create a colorless artifact token named Mind Stone with “{T}: Add {C}” and “{1}, {T}, Sacrifice Mind Stone: Draw a card.”
[–3]: Create Barxbot 9000, a legendary 6/4 colorless Construct artifact creature token with “All damage that would be dealt to Barx planeswalkers you control is dealt to this creature instead.”
[–12]: You and target opponent each gain control of each permanent the other controls that's one or more colors.

{T}: Each of two other target permanents you control that share a card type become a copy of the other until end of turn.

Other Actors you control get +1/+1.
Whenever a permanent you control transforms, Lantern Tender deals 2 damage to any target and you gain 2 life.

Choose a nonlegendary, nonland card name. Target opponent reveals their hand and discards a card with that name.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

For each permanent your opponents control, create a token that's a copy of that permanent.

Whenever Insatiable Abomination or another Horror you control enters, each player mills four cards.
Exile a creature card from your graveyard: Tap target Horror you control. It gains indestructible until end of turn.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Cycling {G} ({G}, Discard this card: Draw a card.)

Each player can't cast more than one spell each turn.
You may cast spells from your hand without paying their mana costs.

[+1]: Create a tapped 3/3 black Crocodile creature token with menace.
[–1]: You may cast a copy of Size Up.
[–7]: Each land you control becomes a 3/3 Crocodile creature and gains menace and haste until end of turn.

Cresting Bay enters tapped unless you control a basic Island.
{T}: Add {U}.
{2}{U}{U}: Until end of turn, Cresting Bay becomes a 3/3 blue Elemental creature with “Whenever this creature attacks, you may draw a card then discard a card.” It's still a land.

When Curious Charter enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)
As a permanent you control explores a land, you may put it onto the battlefield rather than into your hand.

When Recursion Runner enters, create a Function token with “If this spell isn't a copy, copy it. You may choose new targets for the copy.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Trample
Whenever Arisen Tyrant attacks, mill three cards, then you may exile a card from your graveyard. You may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 3 or less.
If Arisen Tyrant would die, exile it instead.

({T}: Add {W}.)
Moon of the Final Dawn enters tapped.
{1}{W}, {T}: Scry 1.

Enchant creature
Enchanted creature gets +2/+2.
Enchanted creature has hexproof as long as it's tapped.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, scry 1, then exile the top card of your library. Until end of turn, you may play that card.