msem-instigator

Equipped creature gets +2/+0.
Equipped creature has first strike as long as it's attacking.
Equip {2}

Choose flying, prowess, vigilance, or ward {2}. Create a colorless Equipment artifact token with “Equipped creature has the chosen ability” and equip {2}. (Then exile this card. You may cast the creature later from exile.)

{T}, Pay 1 life: Add {R} or {W}.
{2}, {T}, Sacrifice Tenement Alley and another permanent: Draw a card. Activate only during your turn.

Reveal the cards in your library. Target opponent chooses three nonland cards with different names from it. You put the chosen cards into your hand. Then shuffle.

Flash
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{W}{B}: Kirishima's Escort gets +1/+1 and gains first strike until end of turn.

Enchant creature
When Yenzu Puppeteering enters, draw a card.
{1}{U}: Untap enchanted creature.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Concord — As long as there are four or more card types among permanents you control, Bubbledome Waveblade gets +1/+1.

Choose two —
• Exile target creature with the greatest power among creatures on the battlefield.
• Target player looks at the top four cards of their library. They put one into their hand, then exile the rest.
• Exile up to four target cards from opponents' graveyards.
• Until the end of your next turn, target player may play cards exiled by Andazir's Command.

Once each turn, when you activate a nonmana ability, you may tap target creature.
{1}{U}: Foggy Town Militia gains flying until end of turn.

You gain 5 life, then you may regenerate target creature. (The next time this would be destroyed this turn, it isn't. Instead tap it.)

Once each turn, when Eruq, the Flamebearer enters or you attack with one or more Horrors, you may have Eruq deal 2 damage to each opponent. Then if Eruq isn't a token, gain control of target creature an opponent controls until end of turn. Tap it. It's attacking its controller.
{2}{R}{R}, Discard Eruq: Create a token that's a copy of Eruq, the Flamebearer, except it's 4/4 and isn't legendary. Activate only as a sorcery.

You may pay {1}{B} and tap an untapped Shaman you control rather than pay this spell's mana cost.
Target player sacrifices a creature. You gain life equal to its toughness.

At the beginning of your end step, if you cast no spells this turn, untap target creature.

Constructed Jay is all colors.
Constructed Jay gets +1/+0 and has flying as long as you control three or more Satrapies.

Target creature fights another target creature. (Each deals damage equal to its power to the other.)

Target creature gains deathtouch and indestructible until end of turn.

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Pressure {6}{U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Take an extra turn after this one. If this spell was cast for its pressure cost, during that turn, whenever you tap an Island for mana, add an additional {U}.
Exile Cuxuri Rift.

Haste
Ward—Pay 3 life.
{R}, Tap an untapped artifact you control: Drysand Mole gets +1/+0 until end of turn. Up to one target creature can't block it this turn.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, up to one other target creature has base power and toughness 0/2 until end of turn.

Target player sacrifices a creature. Then you gain 3 life if that player doesn't control any creatures.

Haste
Whenever Arpechian Tiger attacks, you may sacrifice a land. If you do, Arpechian Tiger deals 3 damage to target creature or planeswalker.

Vigilance
Concord — {G}: Hero of the Stained Blade gets +2/+2 and gains trample until end of turn. Activate only if there are four or more card types among permanents you control and only once each turn.

Target player sacrifices a creature.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Flying, haste
Volcano Tyrant enters with a first strike counter on it.
{2}{R}, Remove a first strike counter from Volcano Tyrant: Double its power and it gains trample until end of turn.