msem-instigator

Target opponent reveals their hand. Choose a nonland card revealed this way. That player discards that card.
You lose 2 life and create a 2/1 black Spirit creature token with “This creature can't block.”

Exile target creature or planeswalker. Its controller may search their library for a creature or planeswalker card and reveal it, then shuffle and put that card on top.

Choose one. If an opponent lost 3 or more life this turn, choose any number instead.
• Target player sacrifices a legendary creature.
• Target player reveals their hand. You choose a nonland card from it. That player discards that card.
• Exile target player's graveyard.

When Karoa's Faithful enters, target creature gets +X/+X until end of turn, where X is the total number of creatures you control that are Knights or have Adventures.

Vigilance
Whenever Karoa's Vanguard or another Knight you control enters, if an opponent controls more lands than you, you may search your library for a Plains card, reveal it, put it into your hand, then shuffle.

Whenever Karoa, His Roaring Grace deals combat damage to a player, if he's not equipped, create a colorless Equipment artifact token named Banner attached to him. The token has equip {1} and “Equipped creature gets +1/+1.”

Equipped creature gets +2/+2.
Whenever equipped creature attacks, the next time an instant or sorcery source you control would deal damage to a creature, player, or planeswalker this turn, it deals that much damage plus 2 instead.
Equip {2}

Lifelink
Engage (This creature must be blocked each combat if able.)

Vigilance, lifelink
{1}, Discard a card: Target Soldier creature gains indestructible until end of turn.

Partner with Shizura, Keeper of Traditions (When this creature enters, target player may put Shizura into their hand from their library, then shuffle.)
Whenever Kasoha, Keeper of Truths or another legendary creature enters, scry 3, then draw a card.

If one or more counters would be put on another permanent you control, put that many counters plus one on that permanent instead.
[+1]: Choose up to one target creature you control. When that creature deals combat damage to a player this turn, draw a card.
[–2]: Choose up to two target creatures. Put a +1/+1 counter on each of them.

At the beginning of your upkeep, put a +1/+1 counter on Kaur's Gift, then you gain life and add {G} equal to its power. You don't lose that mana as steps, phases, and turns end.
When Kaur's Gift dies, you gain life and add {G} equal to its power. You don't lose that mana as steps, phases, and turns end.

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.

Players can't cast spells with mana value greater than the number of dissent counters on Kazimir's Ban.
{2}: Put a dissent counter on Kazimir's Ban. Any player may activate this ability.

Enchant player
When Kazimir's Inquisition enters, enchanted player chooses four card names.
Whenever enchanted player casts a spell, if it doesn't have one of the chosen names, enchanted player loses 4 life.

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.

Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Kederekt Seawitch, then scry 1.

Target Vehicle creature you control deals damage equal to its power to any target. If a creature or planeswalker dealt damage this way would die this turn, exile it instead.

Whenever Keen Blademaster attacks, you may tap target creature.

When Keen Redtail enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
When Keen Redtail dies, it deals damage equal to its power to any target.

Flash
Enchant creature
Whenever enchanted creature becomes the target of an ability or spell you don't control or leaves the battlefield, enchanted creature deals 3 damage to any target.

{1}{G}: Keen Seafarer voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Keen Seafarer phases in, put a +1/+1 counter on it.

{T}: Scry 1.
{1}{U}, {T}: Reveal the bottom card of your library. If it's an artifact or enchantment card, put it into your hand.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Haste
Whenever Keenheart Blade deals combat damage to a player, you may remove a -1/-1 counter from it.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)