msem-instigator

Careless Violence deals 2 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Until end of turn, all creatures gain deathtouch and “When this creature dies, its controller loses 2 life.”

Flash
When Caronas, Eon Wanderer enters, you gain 2 life and draw two cards if Caronas, Eon Wanderer isn't on the battlefield.
{2}{W}{U}, Discard two cards: Aetherize Caronas. (To aetherize, create a token that's a copy of it, then exile that token.)

When Carrion Scythe enters, if you cast it, you may return target creature card from your graveyard to the battlefield, then attach Carrion Scythe to it.
Equipped creature gets +1/+1 and has deathtouch.
Equip {2}

I, II — Scry 2.
Discovery — Whenever a land you control enters, if it doesn't have the same name as another land you control, draw a card.

Vanishing 3 (This permanent enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a time counter is removed from a permanent you control, Carve a Path deals 1 damage to any target.

Glitch {1} (Remove one [restriction] for each time you pay the glitch cost.)
Each opponent loses 3 life, discards a card, sacrifices a creature, then sacrifices a land.
[You lose 3 life.] [Discard a card.] [Sacrifice a creature.] [Sacrifice a land.]

Flash
When Cast Out enters, exile target nonland permanent an opponent controls until Cast Out leaves the battlefield.
Cycling {W} ({W}, Discard this card: Draw a card.)

Reveal cards from the top of your library until you reveal a card with a lesser mana value than the previous card, then put all cards revealed this way into your hand.

Whenever another creature or enchantment you control enters, you gain 1 life.
{3}{W}{W}, Pay 5 life: Castigated Sister becomes a 5/5 Angel Horror with flying. (This effect doesn't end at end of turn.)

{T}: Add {C}.
{B}, {T}, Pay 2 life: Target player mills two cards.
At the beginning of your end step, if your life total is at least 13 less than your starting life total, you may pay {3}{B}{B} and exile this land. When you do, return target creature card from your graveyard to the battlefield.

Choose one. If you're horrific, you may choose both instead. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)
• Destroy target artifact.
• Catastrophic Crash deals 3 damage to target creature.

When Cathar's Armory enters and at the beginning of your first main phase, create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
Whenever one or more creatures you control that are enchanted or equipped deal combat damage to a player, draw a card.

As an additional cost to cast this spell, discard two cards.
Draw three cards.

[+1]: Create a 1/1 red Human creature token with haste.
[–2]: Untap all creatures you control. Until end of turn, they gain “{T}: This creature deals 1 damage to each opponent.”
[–6]: You get an emblem with “Whenever a creature becomes tapped, this emblem deals 2 damage to any target and you gain 2 life.”

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
Whenever Cauldish Arrogant becomes blocked by one or more creatures, reveal the top card of your library. Cauldish Arrogant deals damage equal to that card's mana value to each creature blocking it. Then put that card into your hand.

Bleed {1}{B}{B} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
All creatures get -4/-4 until end of turn.

Haste
Caulte Axeslinger gets +2/+2 as long as any opponent lost exactly 3 life this turn.

Other nonland permanents enter tapped.
Your opponents can't activate abilities of tapped permanents.

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.)
Whenever you cast a spell, if its mana value is less than Cavorting Beauty's power, remove a +1/+1 counter from Cavorting Beauty.

Archive 4 (As this enters, shuffle the top four cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
{1}, Sacrifice a permanent: Put a permanent card with a mana value less than the sacrificed permanent's from the archived library onto the battlefield. Activate only as a sorcery.

[+1]: Untap up to one target creature. It gains deathtouch until your next turn.
[–2]: Target player sacrifices a creature. Return a permanent card from your graveyard to your hand.
[–5]: Put any number of permanent cards from your graveyard onto the battlefield, then sacrifice that many permanents.

Whenever a Soldier or Knight you control enters, you may sacrifice Ceanne's Dawnbringer. If you do, put your choice of two different counters on that creature from among +1/+1, first strike, lifelink, and vigilance.

Ceanne, Shield of Caerdyne enters with your choice of a +1/+1, first strike, lifelink, or vigilance counter.
Counters remain on Ceanne as it moves to any zone other than a player's hand or library.
{3}{G/W}: For each kind of counter on Ceanne, put a counter of that kind on another target creature you control. Activate only once each turn and only as a sorcery.

Whenever a creature enters, if it entered from a graveyard or a player cast it from a graveyard, return Ceaseless Stalker from your graveyard to the battlefield at the beginning of the next end step.