msem-instigator

Bloodprice {B}{B}{B}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Lifelink, haste
Sacrifice another Demon: Jejun, Dark Hunter gains flying and indestructible until end of turn.

Flying
Once during each of your turns, for each creature you control, you may activate one of that creature's activated abilities with {T} in its cost without paying {T} and as though that creature had haste.

Lifelink
Whenever Jerrold, Fugitive or another creature you control enters, if you cast it, you may cast target instant or sorcery card from your graveyard with lesser mana value by paying life equal to its mana value rather than paying its mana cost. Exile that card instead of putting it anywhere else as it resolves.

[+2]: Up to one target creature gets +1/+0 and gains first strike and haste until end of turn.
[–3]: Jeska deals 3 damage to target creature. If that creature is an artifact, she deals 5 damage instead.
[–10]: You get an emblem with “Creatures you control get +2/+0.” and “All creatures have haste and can't block.”

Indestructible
At the beginning of combat on your turn, you may untap target land you control. If you do, that land becomes an X/X green Beast creature with haste until end of turn, where X is the number of differently named lands you control. It's still a land.

When Jobiah, Devoted Farmer enters, search your library for a land card, put it onto the battlefield tapped, then shuffle.
At the beginning of your upkeep, if you control six or more lands with different names, you may transform Jobiah.

Noncreature spells your opponents cast cost {1} more to cast for each counter on Judges of Bearidge.
{5}{W}{U}: Put a +1/+1 counter on Judges of Bearidge, then detain each creature with lesser power. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{1}, {T}: Choose a nonland card name. Reveal the top three cards of your library and put each revealed card with that name into your hand. Put the rest into your graveyard.

Flying
When Kaalia's Abomination enters or dies, it deals 2 damage to target opponent. Then that player discards two cards.

You don't lose the game for drawing from an empty library.
As long as you have seven or fewer cards in each of your libraries, you may cast spells without paying their mana costs.

If a creature would die, exile it instead with an ancestry counter on it.
Kahroba gets +X/+X, where X is the total power of creature cards exiled with ancestry counters on them.
At the beginning of your upkeep, if there are four or more cards exiled with ancestry counters on them, transform Kahroba.

Flying
When Kai'Dwo, Eternal Ravager enters, create seven Idol tokens. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Whenever you sacrifice an Idol, each opponent sacrifices a creature.

Flying
Ward—Discard a card.
Whenever Kai'Oro enters or attacks, you may exile target nonland card with mana value 3 or less from your graveyard. Until end of turn, you may cast a copy of that card without paying its mana cost.

Flash
When Kaivilu, Ocean Warden enters, creatures your opponents control get -2/-2 and lose all abilities until end of turn.

[+1]: Discard a card. If you do, each opponent discards a card and loses 1 life.
[–3]: Destroy target creature or planeswalker.
[–7]: Draw a card for each creature card and planeswalker card in all graveyards. Target opponent loses that much life.

As long as there are seven or more loyalty counters on Kalemn, she has lifelink and deathtouch.
[+2]: Kalemn deals 2 damage to each opponent.
[+1]: Kalemn deals 1 damage to target creature or planeswalker.
[–7]: For each opponent, Kalemn deals 3 damage to that player unless they discard a card. Repeat this process six times.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
You may play any number of lands on each of your turns.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
At the beginning of each player's upkeep, they sacrifice a nonenchantment creature. Then if there are no nonenchantment creatures on the battlefield, sacrifice Kantra of Plagues.

When Kaone enters, if it was cast, exile target instant or sorcery card from your graveyard. If its mana value is less than or equal to the number of spells you've cast this turn, you may cast a copy of that spell without paying its mana cost. If you don't cast a copy this way, put the exiled card into your hand.

Indestructible
As long as your devotion to green and white is less than seven, Karametra isn't a creature.
You may play an additional land on each of your turns.
As you begin searching your library, you may reveal a basic land card from your library and put it into your hand.

Whenever you make first contact, you may activate one of Karina's loyalty abilities. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)
[+1]: Each player draws a card.
[–2]: Exile target nonland permanent. At the beginning of the next end step, return it to its owner's hand or to the battlefield under its owner's control.
[–7]: You get an emblem with “You may cast spells that don't have the same name as a permanent you control or a card in your graveyard without paying their mana costs.”

Kaur, End of Lies costs {X} less to cast, where X is the greatest mana value among permanents your opponents control.
[+2]: Reveal the top card of your library. If it's a permanent card, put it onto the battlefield.
[–4]: Exile target noncreature permanent, then reveal the top four cards of your library. You may put a permanent card from among them onto the battlefield. Put the rest into your graveyard.
[–12]: Search your library for up to X permanent cards, where X is the number of permanents you control, put them onto the battlefield, then shuffle.

Whenever you cast an instant or sorcery spell, Kederekt Deepdweller gains your choice of indestructible, lifelink, or menace until end of turn.
Whenever Kederekt Deepdweller deals combat damage to a player, you draw a card and that player discards a card.

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast artifact spells. Activate only if you control three or more artifacts.

[+1]: Create a 1/1 colorless Thopter artifact creature token with flying. It gains lifelink until your next turn.
[–1]: Sacrifice an artifact. If you do, draw two cards.
[–6]: Draw seven cards. Artifact spells you cast this turn cost {2} less to cast.