msem-instigator

Draw three cards. Then discard two cards unless you return a permanent you control to its owner's hand.

{T}: Conchspear Hunter deals 1 damage to any target. Activate only if you control three or more artifacts.

Destroy target creature. (Cast a copy of this spell once while this creature is on the battlefield.)

{T}: Add {G} or {W}. You lose 1 life unless you have less life than an opponent.

When Condemned Cavalier enters, create a white and black Aura Curse enchantment token named Profane March attached to target player. The token has enchant player and “Whenever a creature enchanted player controls attacks, that player loses 1 life and defending player gains 1 life.”

Ferocious — At the beginning of your first main phase, if you control a creature with power 4 or greater, add {R}.

At the beginning of combat on your turn, you lose 1 life and rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

Other Knight creatures you control get +1/+1.

Enchant creature
Enchanted creature is a blue Shaman with base power and toughness 0/2, has “{2}, {T}: Scry 1,” and loses all other abilities.

When Confine to the Oasis enters, exile target nonland permanent an opponent controls until Confine to the Oasis leaves the battlefield.
Whenever an opponent casts a spell, put a searching counter on Confine to the Oasis for each of that card's colors. Then if there are ten or more searching counters on Confine to the Oasis, sacrifice it and you gain 3 life.

When Confining Priest enters, exile another target creature with power 4 or less an opponent controls until Confining Priest leaves the battlefield. (That creature returns under its owner's control.)

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

When Conflux Ravager enters, destroy target nonland permanent an opponent controls.
Cycling {2} ({2}, Discard this card: Draw a card.)

(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 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.

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.)

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.

Draw three cards.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

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.

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.”