msem-instigator

Enchant creature
Enchanted creature has winnow. (Damage dealt to it also causes its controller to lose that much life.)

As an additional cost to cast this spell, sacrifice a creature.
Draw cards equal to the sacrificed creature's power.

Whenever a creature you control perseveres, you draw a card and you lose 1 life. (A creature perseveres when it's dealt damage and doesn't die.)
{1}{B}: Deathmask Initiation deals 1 damage to target creature you control.

Target creature gets -2/-2 until end of turn.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, return up to one target enchantment card from your graveyard to your hand.

When Debt Dignitary enters, tap target nonland permanent. That permanent doesn't untap during its controller's untap step for as long as you control Debt Dignitary.

Decayed Bedchamber enters tapped.
When Decayed Bedchamber enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {B} or {G}.

Whenever Deceitful Soul becomes blocked by one or more creatures, it gets +2/+0 until end of turn.

Primal {B}{B} (During your turn, you may cast this spell for {B}{B} instead of playing a land.)
Search your library for a card and put that card into your hand, then shuffle. Exile Deceitful Tutor.

Target creature gets +2/+2 until end of turn. You may remove a -1/-1 counter from it.

Target opponent discards a card. If a creature card was discarded this way, that player loses 3 life. If a land card was discarded this way, add {B}{B}. If a noncreature, nonland card was discarded this way, draw a card.

Creatures you control get +2/+2 and gain vigilance and trample until end of turn.

Menace (This creature can't be blocked except by two or more creatures.)

Counter target creature spell, planeswalker spell, or activated ability.

{T}, Sacrifice Decrepit Crags: Search your library for a Swamp or Mountain card and put it onto the battlefield tapped, then shuffle.

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.)

Haste
When Dedicated Bushwacker enters, other creatures you control get +1/+0 and gain haste until end of turn.

{T}: Add {G}. If a -1/-1 counter was put on a creature you control this turn, add {G}{G} instead.

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

When Dedicated Waypoint enters, create a 1/1 white Scout creature token.
{T}: Add {R}, {W}, or {B}.

Draw a card. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Counter target spell with mana value 3 or less. If a spell is countered this way, return it to its owner's hand instead of putting it anywhere else.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player mills a card.

Exile target creature. Return that card to its owner's hand at the beginning of its owner's next end step.

Deep-Sea Terror can't attack unless seven or more cards are in your graveyard.

Flash
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)