msem-instigator

Whenever you cast a spell, harmonize twice. (To harmonize, trigger up to one harmony of a permanent you control.)
Harmony — Yita, Almgrove Prodigy gains your choice of flying, first strike, vigilance, lifelink, hexproof, or haste until end of turn.

When Solar Pact enters, return up to two cards with different mana values from your graveyard to your hand.
Each player can't draw more than one card each turn.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{U}{R}: Target creature without prowess gains prowess until end of turn. Activate only if Intelligence is in your graveyard.

Prowess
Whenever you cast a noncreature spell, target creature can't block this turn.

Whenever an opponent activates an ability of a nonland permanent, destroy that permanent.
{3}{U}{B}{R}: Exile target creature or planeswalker card in a graveyard. Create a token that's a copy of it.

Destroy target attacking creature.

At the beginning of each combat, up to one target creature can't attack or block this turn.

Deathtouch
At the beginning of your end step, create a 1/1 black Rat creature token with “This creature can't block.”
{1}{B}, {T}, Sacrifice three other creatures: Each opponent discards a card and loses 2 life. You draw a card and gain 2 life.

Search target opponent's library for an artifact card and put it onto the battlefield under your control, then that player shuffles. If you don't put a card onto the battlefield this way, create four Gold tokens. At the beginning of the next end step, sacrifice each artifact put onto the battlefield this way. (This includes the Gold.)

Enchant creature
Enchanted creature can't block.
Whenever enchanted creature attacks an opponent, it gets +2/+2 until end of turn.

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Target creature you control gets +2/+2 until end of turn. If it's attacking, it gains indestructible until end of turn.

Spend only black mana on X.
Up to two target creatures each get -X/-X until end of turn. You gain X life.

As an additional cost to cast this spell, discard a card.
Draw two cards. Add one mana of any color.

When Elderthrone Castellan enters, you may search your library for a Plains card, reveal it, put it into your hand, then shuffle.

Whenever you cast a spell, put a charge counter on Astral Dynamo.
{T}, Remove any number of charge counters from Astral Dynamo: Add that much {C}.

Tap up to two target creatures.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

Enchant creature
Enchanted creature gets +2/+2.
Whenever enchanted creature attacks, create a 2/2 white Knight creature token that's tapped and attacking.

Target attacking creature fights another target attacking creature.

Equipped creature gets +3/+0 and has vigilance.
Equip {3}

Majestic Tomb enters tapped.
{T}: Add {B} or {R}.
When Majestic Tomb enters, you may put a loyalty counter on a planeswalker you control.

Flying
At the beginning of each combat, target opponent may give themselves a poison counter. If they don't, Tower of Sorrows gets +3/+0 until end of turn.

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a card from the archived library, put the top card of your main library on the bottom of the archived library.
{U}: Exchange a card from the archived library with a card from your hand.

Create a 1/1 white Peasant creature token if you control a Citizen or Peasant. Then Byron's Reprisal deals damage equal to the number of creatures you control to up to one target creature or planeswalker.

Whenever a creature you control dies, you may pay {G}. If you do, draw a card.