msem-instigator

Once each turn, when a creature you control attacks alone, you may untap target attacking creature. After this combat, there's an additional combat step.

At the beginning of your upkeep, you may sacrifice another creature. If that creature had mana value 2 or greater, create a 3/2 colorless Horror creature token. Otherwise, create a 1/1 colorless Human creature token.
Whenever you create a creature token, you may pay 2 life. If you do, put a menace counter on it.

As Chromatic Interloper enters, choose two abilities from among first strike, menace, vigilance, trample, or haste.
Creatures you control with mana value 5 or greater have the chosen abilities.

Flying
{2}{U}: Until end of turn, target creature has your choice of base power and toughness 1/1 or 4/4 until end of turn. Activate only outside of combat.

Each player discards their hand and sacrifices five lands. Cinders of an Old Era deals 5 damage to each creature and planeswalker.
At the beginning of each player's next first main phase, that player draws seven cards and adds five mana in any combination of colors.

When Climber's Outfit enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Equipped creature has reach.
Equip {1}

Flash
When Comforting Presence enters, return target spell with mana value 2 or less to its owner's hand.
Whenever an opponent casts their second spell each turn, draw a card.

Target creature you control deals damage equal to its power to up to one other target creature. Then if you've cast another spell this turn, the creature you control gains double strike until end of turn.

At the beginning of combat on your turn, you may exile a creature card from your graveyard. Then if a card exiled with Concoquo has flying, creatures you control gain flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

When Confident Traveler dies, create a 1/1 white Human creature token. If Confident Traveler was sacrificed, create two of those tokens instead.

Flying
At end of combat on your turn, untap all creatures you control with power greater than their base power.

When Conscious Taboo enters, look at target opponent's hand. You may exile a noncreature, nonland card from it. For as long as that card remains exiled, its owner may play it. A spell cast this way costs {2} more to cast.

Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Draw a card.

Menace
Sacrifice another creature: Corpulent Gibberer deals 1 damage to any target.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

This spell costs {1} less to cast for each card type among cards in your graveyard.
Deathtouch

Flash
When Cranial Glass enters, exile target card from a graveyard.
{7}, {T}, Sacrifice Cranial Glass: Copy the exiled card. You may cast the copy without paying its mana cost. (A copy of a permanent spell becomes a token.)

Menace, haste, decayed (This can't block. When it attacks, sacrifice it at end of combat.)
At the beginning of combat on each of your turns, if you have three or more creature cards in your graveyard and haven't controlled a creature named Crypt Gnawer this turn, return Crypt Gnawer from your graveyard to the battlefield.

{T}: Add {C}.
{X}: Crypt of Myriad Fates becomes a copy of target creature card with mana value X or less in your graveyard until end of turn, except it's 2/2 and a land in addition to its other types. Activate only outside of combat.

Elemental, Demon, and Spirit spells you cast cost {1} less to cast.
Whenever you cast a Elemental, Demon, or Spirit spell, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Enchant player
At the beginning of enchanted player's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

[+1]: Add two mana of any one color.
[0]: Put two +1/+1 counters on target creature you control. Then put your choice of a reach, vigilance, or trample counter on it. If you have an insight counter, you may put all of those counters on that creature instead.
[0]: You get an insight counter.
[–2]: Destroy target noncreature, nonland permanent.

Each creature can't have power greater than its base power and can't have toughness greater than its base toughness.

You may exert Deathmarked Explorer as it attacks. When you do, it gets +X/+X until end of turn, where X is 10 minus your life total. (An exerted creature won't untap during your next untap step.)
{T}, Discard a card: Draw a card. Deathmarked Explorer deals 2 damage to you.

When Decrepit Hero dies, create a 2/2 black Soldier creature token.
Fleeting {1}{B} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Target creature gets +1/+0 and gains first strike until end of turn.
Target creature blocks this turn if able.