msem-instigator

Flying
You may cast black spells with mana value 3 or less by paying life equal to their mana values rather than paying their mana costs.
{B}, Sacrifice another creature: You gain 3 life.

Flying
Kai'Wej, the Desolate has indestructible as long as you control no other creatures.
{1}{B}{B}, Sacrifice two creatures: Return Kai'Wej from your graveyard to the battlefield tapped.

Menace
When Kai'Zhou enters, you may have all legendary nonland permanents phase out until your next turn.
Whenever Kai'Zhou deals combat damage to a player, they sacrifice a legendary permanent.

Whenever a creature attacks you or a planeswalker you control, put that creature on the bottom of its owner's library unless its controller pays {2}.

When Kalak Culler enters, each opponent loses life equal to the number of creatures you've sacrificed this turn.
Revive—{3}{B}, Sacrifice a creature. ({3}{B}, Sacrifice a creature, 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.)

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell that's three or more colors.

Kalib Kabir has hexproof as long as it has no +1/+1 counters on it.
Kalib Kabir has trample as long as it has a +1/+1 counter on it.
{G}: If Kalib Kabir has a +1/+1 counter on it, remove all +1/+1 counters from it. Otherwise, put a +1/+1 counter on it. Activate only once each turn and only during your turn.

Enchant creature
When Kalku Initiation enters, you lose 3 life and discard a card.
Enchanted creature gets +3/+2, has ward {2}, and has “Whenever this creature deals damage to a player, draw two cards.”

Prismatic — Whenever you cast a multicolored spell, if you cast it from your hand, look at the top four cards of your library. You may cast a multicolored card that's different colors and costs less from among them without paying its mana cost. Put the rest on the bottom of your library in any order.

Whenever a creature attacks Kalro, Desert Outpost, it deals 1 damage to that creature.
[+1]: Create a 1/1 red and white Sand Warrior creature token.
[–2]: Destroy target nonbasic land. Its controller creates a colorless Desert land token with “{T}: Add {C}.”

Changeling (This card is every creature type.)
As Kalyn, Wildkin Envoy enters, choose up to three non-Human creature types.
Other creatures you control with one or more of the chosen types get +1/+1.
{2}, {T}: Create a 1/1 colorless Shapeshifter creature token with changeling. Activate only outside of combat.

Flying, haste
Ward—Pay 3 life.
The first Dragon spell you cast each turn costs {R}{R} less to cast. (This can reduce the amount of generic mana you pay.)

{W/B}: Kambiro, the Untrue King gets +1/+1 until end of turn.
Whenever a storied permanent you control enters, if you cast it, return target creature card from your graveyard to your hand. If that creature's power is less than Kambiro's power, you may return it to the battlefield instead. (Enchantments and legendary permanents are storied.)

Lifelink, first strike
You may cast creature spells from your graveyard if their mana value is less than or equal to the amount of life you have gained this turn. Whenever you cast a creature spell this way, it enters with a finality counter on it.

Prowess
You may activate inscribe abilities from your graveyard as though they were in your hand.

Haste, prowess
Whenever Kamito Warcaster attacks, you may pay {2}{R}. If you do, create a token that's a copy of another target creature you control and that's tapped and attacking. It's a colorless Spirit in addition to its other types. Exile that token at end of combat.

{T}: Gain control of target creature or planeswalker with mana value less than or equal to Kan'Gi's power for as long as you control Kan'Gi.
Inspired — Whenever Kan'Gi becomes untapped, put a +1/+1 counter on her.

Whenever Kan'Gi, the Reverent perseveres, gain control of target creature an opponent controls with power less than or equal to Kan'Gi's power. (A creature perseveres when it survives damage.)

Rhapsody {5}{R}{W} (Pay {5}{R}{W} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Whenever a creature you control with power 4 or greater attacks, look at the top four cards of your library. You may cast a nonland card with mana value 3 or less from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

{T}: Add {C}.
Satrapies you control have “{1}{B}, {T}: Each opponent loses 1 life and you gain 1 life.”

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.)
When Kantra of Old Majik enters, you may return target card from your graveyard to your hand.

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 look at the top card of your library any time.
You may play the top card of your library.

Kanvar can't attack or block.
Whenever a creature you control with power 4 or greater dies, draw a card.
{R}{G}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words “when,” “whenever,” or “at.”)

Flying, haste
Whenever a nonbasic land becomes tapped, it deals 2 damage to its controller.
Whenever Kaor Awoken attacks, it gets +1/+0 until end of turn for each other Dragon you control.

Whenever an opponent casts a noncreature spell, create a Treasure token. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)