msem-instigator

Flash
When Scorned Arcanist enters, until end of turn if a creature would enter the battlefield, instead exile that creature and that creature's controller amasses Soldiers X, where X is that creature's mana value. (They put X +1/+1 counters on an Army they control. It's also a Soldier. If they don't control an Army, they create a 0/0 black Soldier Army creature token first.)

Destroy all artifacts with mana value X or less. Whenever an artifact is destroyed this way, Calamitous Crash deals 1 damage to any target.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{3}{G}: Da'Lang gets +2/+2 until end of turn. If you're in a renaissance, all creatures able to block Da'Lang this turn do so. Activate only once each turn.

Until end of turn, target creature gets +2/+0 and gains “When this creature dies, return it to the battlefield tapped under your control.”

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Towering Wickerman can't be blocked by creatures with power 2 or less.
Whenever a creature merges with Towering Wickerman, put two +1/+1 counters on it.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Destroy target creature that was dealt damage this turn, then create a 3/2 black Mutant Horror creature token.

Spearhead deals X damage to target player. (Then exile this card. You may cast the creature later from exile.)

First strike
Whenever Deprived Div deals combat damage to an opponent, end the turn. (Creatures without first strike won't deal damage this turn.)

Pressure {G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Return target card from your graveyard to your hand. Exile Drawn to the Light.

As Battle the Evil One enters, choose Evil One or Rehison.
• Evil One — Zombie creature cards in your graveyard have unearth {3}{B}. ({3}{B}: Return this card from your graveyard to the battlefield. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)
• Rehison — Whenever an Elf you control enters, you may put a -1/-1 counter on target creature.

Foretell {X}{B} (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.)
Target creature gets -X/-X until end of turn. If this spell was foretold, you gain X life.

Augmented — When Behavioral Specialist enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, create a 1/1 blue Elemental creature token with flying.
Whenever one or more creatures you control deal combat damage to an opponent, you may draw a card. If you do, discard a card.

[+1]: Artifact creatures you control get +1/+1 and gain haste until end of turn.
[–X]: You may cast an artifact card with mana value X or less from your hand without paying its mana cost. If it has {X} in its cost, {X} is X.
[–6]: Choose a number. For each artifact you control with the mana value equal to the chosen number, create a token that's a copy of it.

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, you may exile it. If you do, return target creature card from your graveyard to the battlefield.

Trample
Other Beasts you control have trample.
Whenever Magnoceros attacks, create a 5/5 green Beast creature token that's tapped and attacking.

Reverberate {3} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Target creature can't block this turn.
Target creature can't be blocked this turn.

When Colony Queen enters, create three 1/1 green Insect creature tokens.
Insect tokens you control have flying and deathtouch.

Whenever you attack, put a hatching counter on Greatwyrm's Egg. Then you may sacrifice it. If you do, create a tapped and attacking X/X red Dragon creature token with flying and haste, where X is the number of hatching counters on Greatwyrm's Egg.

When this creature enters, draw a card.

When Flamboyant Inventor enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”
At the beginning of each combat, you may have Powercells you control become 2/2 Construct creatures with vigilance in addition to their other types until end of turn.

Reveal the top card of your library. You may put it on the bottom of your library. Target creature gets -X/-0 until end of turn, where X is that card's mana value.

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
Other creatures you control have lifelink.
Each player and cards in graveyards can't be the targets of spells or abilities your opponents control.

Flying
When Sage of Dilemmas enters, return up to one target enchantment to its owner's hand.

Ashthread Alley enters tapped.
{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice Ashthread Alley: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)