msem-instigator

Target creature gets +2/+2 for each creature blocking it and gains trample until end of turn.
Fuse (You may cast one or both halves of this card from your hand.)

Whenever attackers are declared, defending player may pay 2 life for each creature you control attacking them. Then target creature gets -X/-X until end of turn, where X is the number of times that player didn't pay life this way.

Counter target spell unless its controller pays {X}. Scry 2.

{B}, {T}: Destroy target tapped creature.

Lands you control have “{T}: Add one mana of any color.”
{T}: Add one mana of any color.

Lifelink
Revive {W} ({W}, 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.)

Whenever Wakeborne Kraken or another Kraken, Leviathan, Octopus, or Serpent you control enters, you may return target creature an opponent controls to its owner's hand.
Whenever a creature an opponent controls leaves the battlefield, if it didn't die, draw a card.

Whenever an enchantment you control enters, target opponent loses 1 life and you gain 1 life.

Play with the top card of your library revealed.
Whenever you draw a card, destroy each creature with the same mana value as that card.

When Warden of Rehis-Dorahn enters, put a -1/-1 counter on each creature.
{2}{B}{G}, {T}: Destroy target creature with a counter on it.

At the beginning of your end step, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

[+1]: Augur. (Look at the top card of your library. You may sacrifice a creature to put it into your hand. Otherwise, put it back or put it into your graveyard.)
[–X]: Exile target card in your graveyard with mana value X. Copy it. You may cast the copy without paying its mana cost.
[–6]: You get an emblem with “Whenever a creature you control dies, search your library for a creature card, reveal it, and put it into your hand, then shuffle.”

When Fireheart Channeler dies, you may exile it. If you do, put a blaze counter on target land without a blaze counter on it. As long as that land has a blaze counter on it, it has “At the beginning of your upkeep, this land deals 1 damage to you.” (The land continues to burn after Fireheart Channeler has left the battlefield.)

Primal {W} (During your turn, you may cast this spell for {W} instead of playing a land.)
Destroy target attacking or blocking creature.

Defender
When Dispossessed Noble enters, draw a card.

Flying, vigilance
Whenever Etherwrought Figurehead attacks, you may pay 4 life. If you do, destroy target tapped creature.
If Etherwrought Figurehead would leave the battlefield, exile it instead.

Exile the top two cards of your library. Until the end of your next turn, you may play those cards. (If you cast a spell this way, you still pay its costs. You can play a land this way only if you have an available land play remaining.)

Whenever Treasure Hauler attacks, draw a card.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Whenever a nontoken creature you control enters, you may scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

{1}{U}: Mercurial Merfolk gets +2/-2 until end of turn.
When Mercurial Merfolk dies, draw a card.

Once each turn, when another creature dies, you may crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)
Whenever an artifact you control dies, Nihilistic Shock Trooper deals 1 damage to each opponent.

Reach
At the beginning of your end step, if you've gained 3 or more life this turn, create a 3/3 black Demon Horror creature token and each player loses 3 life.

Choose target creature you control. If it has a +1/+1 counter on it, put an additional +1/+1 counter on it. Then it fights target creature you don't control.

Flash
If an opponent would gain life or damage to a permanent or opponent would be prevented, instead Spirit-Lantern Incendiary deals 1 damage to that permanent or opponent.

Enchant land you control
Whenever enchanted land is tapped for mana, it produces an additional mana of that type.
{1}{G}, Sacrifice Under Untamed Skies: Destroy target creature with flying.