msem-instigator

Counter target spell.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Target creature gets +2/+0 and gains first strike until end of turn. If it's attacking a battle, it gains double strike until end of turn.

{W}, {T}: Tap target creature.

Embellish {3}{B} (If you cast this spell for {3}{B}, create a 1/1 blue Thopter artifact creature token with flying when it enters.)
When Scrap Spiral enters, target creature gets -2/-2 until end of turn.
{3}{B}, {T}, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.

Menace
Whenever Operative GINGER attacks or you cast a blue or white spell, Operative GINGER deals 1 damage to any target.

As Den of Vice enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}, {B}, or {R}.

Flash
Enchant creature
As Legacy of Northrime enters, choose a creature type.
Enchanted creature gets +1/+4 and is the chosen type in addition to its other types.

Flying, hexproof
At the beginning of your end step, put an exiled card with an ancestry counter on it on the bottom of its owner's library, then scry 2. If there is exactly one card exiled with an ancestry counter on it, transform Atieh.

Flying
Whenever an opponent discards a card, put a +1/+1 counter on Nightbane Specter.
Whenever Nightbane Specter deals combat damage to a player, that player discards a card.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {B} or {G}.

Prowess
Pay 2 life: Change a target of target spell or ability to Straw Intellectual.

Trample
When Ghastly Progenitor enters, each opponent reveals their hand. Choose two nonland cards revealed this way. Their owners discard those cards.

Target player sacrifices an attacking creature. You gain life equal to that creature's power.

Whenever Combat Technician attacks, create a 1/1 colorless Servo artifact creature token that's tapped and attacking. Then Combat Technician gets +1/+1 until end of turn for each artifact you control.

Defender
As long as you control an enchantment, Rooted Cavalier has vigilance and can attack as though it didn't have defender.

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast artifact spells. Activate only if you control three or more artifacts.

Flying
When Foul Vulture enters, create a 1/1 red Hound creature token.
Foul Vulture gets +1/+0 as long as a creature you controlled died this turn.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
If you would draw a card from an archived library, draw a card from each of your archived libraries instead. (Archived libraries are those that still have their Study in play.)

When Dthan's Daggers enters, you may attach it to target creature you control.
Whenever equipped creature attacks, it gets +3/+0 and gains first strike until end of turn.
Equip {3}{R}

(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 Nizev enters, draw three cards.
When Dawn Over Nizev is defeated, exile it. If you do, you may cast a spell from your hand without paying its mana cost.

Target player discards two cards. If a creature you control died this turn, that player loses 2 life.

{T}: Target player loses 1 life.
Whenever you cast a spell from your graveyard, untap Paincaller.

{T}: Add {C}.
{2}, {T}: Draw a card. Activate only if you have no cards in hand.

Whenever Byway Bruiser enters or leaves the battlefield, you may have it deal 3 damage to any target.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Jutou enters with X +1/+1 counters on her.
{3}{G}: Demigod — You gain life equal to the greatest power among creatures you control.
{6}{G}: God — Search your library for a creature card with the same power as a creature you control, put it onto the battlefield, then shuffle.