msem-instigator

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.

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.)

Target creature gets -4/-0 until end of turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Exile target creature if its controller controls more lands than you.
Cycling {2} ({2}, Discard this card: Draw a card.)

Enchant artifact or creature
Enchanted permanent can't attack and its activated abilities can't be activated.

When Keeper of Blue Incense enters, submerge target card from your graveyard. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Flash
When Keeper of Codices enters, you may exile target artifact or enchantment you control. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step.

When Keeper of Dark Shadows enters, if it's not a token, target opponent reveals their hand. You may choose a creature card from it. Create a token that's a copy of that card, except it's a colorless Spirit.

When Keeper of Pearls enters or a creature scavenges it, you gain 2 life.
Scavenge {G} ({G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Ward {2}
Whenever one or more Auras you control enter for the first time each turn, adjudicate. (Create a white enchantment Aura token with enchant creature and “Sacrifice this token: Untap enchanted creature.” attached to target creature.)
Keeper of Secret Havens gets +1/+1 for each Aura you control.

Whenever one or more other creatures you control die, put a +1/+1 counter on Keeper of Tradition.

When Keeper of the Ancient Ways enters, destroy up to three target noncreature, nonland artifacts and/or enchantments with total mana value 3 or less.

First strike
Whenever Keeper of the Banner deals combat damage to a player, draw two cards, then discard two cards.

Whenever you cast a spell from exile, copy that spell. You may choose new targets for the copy.
{B}, Discard a card: When you next cast a spell from your hand this turn, it gains rerun. Activate this ability only once each turn. (Exile it as it resolves if you cast it from your hand. Whenever a creature you control dies, you may cast that card from exile without paying its mana cost.)

{T}: Keepers of the Reach deals 1 damage to each opponent.
{2}{R}, {T}: Keepers of the Reach deals 3 damage to each opponent. Activate only if you control a permanent with mana value 5 or greater.

As an additional cost to cast this spell, return any number of creatures you control to their owner's hands. This spell costs {2} less to cast for each creature returned in this way.
Trample, ward {3}
Keepers of the Rundfora's power and toughness are each equal to twice the number of cards in your hand.

At the beginning of each player's upkeep, that player loses 2 life unless they sacrifice a creature.
{4}{G}: Create a 2/2 green Wolf Elemental creature token.

When Keepsake of Binding enters, exile target creature an opponent controls until Keepsake of Binding leaves the battlefield.
{4}, {T}: Tap target creature with power less than the exiled card's power.

This spell costs {1} less to cast for each permanent you control that's an artifact and/or a token.
When Kellythross's Collector enters, you may return another target nonland permanent to its owner's hand.