msem-instigator

Target creature you control deals damage equal to its power to target creature you don't control. For each point of excess damage dealt this way, put a +1/+1 counter on the creature you control.

Concord — At the beginning of your upkeep, if there are four or more card types among permanents you control, you gain 1 life and create a 1/1 blue Jellyfish enchantment creature token with slipstream. (It can't be blocked as long as only creatures with slipstream are attacking.)

Indestructible
As long as your devotion to blue and red is less than seven, Keranos isn't a creature.
Whenever you cast an instant or sorcery spell, you may copy that spell. Do this only once each turn. You may choose new targets for the copy.

When Monstrous Hunter enters, destroy up to one target creature.
At the beginning of each end step, if a creature died this turn, you draw a card and you lose 1 life.

Mortal Realms enters tapped unless you control two or more other lands.
{T}: Add {R}.
{T}, Pay 1 life: Add {B} or {G}.

Assault {X}{R}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Other Elementals you control get +1/+0.
When Unbound Annihilus assaults, create X 1/1 red Elemental creature tokens that are tapped and attacking.

Put target permanent card from a graveyard onto the battlefield under your control.

Enchant creature
You control enchanted creature.
When Shahmaran's Captivation enters, untap enchanted creature. It gains haste until end of turn.

Haste
{T}, Sacrifice a creature: Ashspeaker deals 1 damage to any target.

Flash
When Shadow Stalker enters, for each player, look at the top card of that player's library. You may have that player put that card into their graveyard.

When Rocket Admin enters, you may pay 3 life. When you do, gain control of target creature or planeswalker with mana value 3 or less until its owner pays {3}.

As an additional cost to cast this spell, exile X cards from your graveyard.
You draw X cards and you lose X life.
Coalesce {8}{B} (You may cast this from your graveyard for {8}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

When Dabbling Patron enters, if you cast an instant or sorcery spell this turn, create a 1/1 colorless Elemental creature token.

Exile target artifact or enchantment. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Flying
When Mother of Owls dies, you may return target creature an opponent controls to its owner's hand.

You may have Urushi, the Ripple in the Smoke enter as a copy of any creature on the battlefield, except it's an enchantment. (It's not a creature.)

Equipped creature gets +1/+1 for each permanent attached to it and has trample.
Equip {4}

Whenever another creature you control dies, target player loses 1 life and you gain 1 life.
{1}{B}, Sacrifice a creature: Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

{2}{R}: Target creature can't block this turn.

Enchant player
Whenever one or more creatures attack enchanted player, their controller may sacrifice a creature. If they do, enchanted player loses 3 life, sacrifices a nonland permanent, and discards a card.

Menace
Whenever Dragon's Twisted Shadow attacks and isn't blocked, it gets +4/+0 until end of turn.

Golden Glade enters tapped.
{1}, {T}: Add two mana of any one color.

Flash
When Swift Savior enters, if you control a legendary creature, you may have Swift Savior deal 2 damage to target attacking or blocking creature.

Blazing Volley deals 1 damage to each creature your opponents control.

{X}{W}{W}: Prevent the next X damage that would be dealt to target creature you control this turn. Whenever damage is prevented this way, you gain that much life.