msem-instigator

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you attack with one or more creatures with power 4 or greater, add a quest counter.
Until end of turn, target creature you control gains trample and “Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.”
Put two +1/+1 counters on target creature you control. It fights up to one target creature you don't control.

When Conquerer's Blade enters, create a 1/1 white Soldier creature token and attach Conquerer's Blade to it.
Equipped creature gets +1/+0 and has first strike.
Equip {3}

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.

Create three 1/1 white Soldier creature tokens. Scry 3.

Create a 1/1 white Soldier creature token with vigilance.
At the beginning of combat on your turn, you may pay {2}{W}. If you do, creatures you control get +1/+1 until end of turn.

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

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Destroy target creature. If you're in a renaissance, you may return a creature card from your graveyard to your hand.

Menace
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Lifelink
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Vanishing 1 (This permanent enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When the last time counter is removed from Conspiracy of Ravens, target player reveals their hand. You choose a nonland card from it. That player discards that card.

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

Create two 1/2 blue Bird creature tokens with flying.
Coalesce {5}{U}{U} (You may cast this from your graveyard for {5}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Look at the top card of your library. You may put it into your graveyard. Repeat this process twice, then draw a card.

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

Look at the top four cards of your library. You may reveal a noncreature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Civilized — This spell costs {1} less to cast if you control an artifact, a creature, and an enchantment.
Counter target spell.

Consume Creation deals 2 damage to any target and you gain 2 life.

Consuming Flame deals 6 damage to target creature.
Ferocious — If you control a creature with power 4 or greater, the damage can't be prevented and that creature can't be regenerated this turn.

Bloodprice {2}{U} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Draw two cards. If you cast this spell for its bloodprice, instead scry 4, then draw two cards.

When Consumption Catalyst enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Whenever you draw a card, each opponent loses 1 life and you gain 1 life.

When Contagious Host dies, each player loses 1 life.
Revive {2}{B} ({2}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Destroy target artifact or enchantment. Create a 1/1 green Saproling creature token.

Prowess
{1}{U}, Tap an untapped Wizard you control: Target creature gets -3/-0 until end of turn.

Enchant creature
Enchanted creature gets +2/+1 and has “Whenever this creature attacks, target creature an opponent controls can't block this turn.”

Trample
When Contentious Yak enters, another target creature you control gets +1/+1 and gains trample until end of turn.