msem-instigator

Destroy all creatures. Exile all graveyards.

Untapped creatures you control get +1/+1.
Soldiers you control have vigilance.

Reach (This creature can block creatures with flying.)

Descended Marsh enters tapped.
{T}: Add {B} or {G}.
Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

When Glowspore Swarmgrounds enters, create two 1/1 blue Elemental creature tokens with flying.
Elementals you control get +1/+1.

Flying
When Pyre Apostle enters, discard your hand, then draw three cards.
Madness {3}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

When The Struggle for Death enters, choose target creature you don't control. Any number of creatures you control fight that creature.
Whenever a creature dies, look at the top card of your library. You may put it into your graveyard.

Menace
Once during each of your turns, when you sacrifice a permanent, you may put a +1/+1 counter on Assimilated Runner.

Enchant creature
Enchanted creature is a Horror with base power and toughness 3/3 and loses all other creature types and abilities.
Whenever enchanted creature deals combat damage to a creature, create a token that's a copy of Plagas Infestation and attach it to the damaged creature.

Menace
Whenever Auros, Flame-Cursed attacks, it deals 3 damage to each opponent.

Whenever Ore Tunneler deals damage to an opponent, tap target land they control. It doesn't untap during its controller's next untap step.

Flash

When Night Shepherd enters, return a creature you control to its owner's hand.

Counter target spell that targets you or a permanent you control. If that spell targeted a creature, put a +1/+1 counter on that creature.

Neo-Soul Nihilist has lifelink as long as it's attacking.
When Neo-Soul Nihilist is put into your graveyard from anywhere, you may pay 2 life. If you do, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

(Transform this if it's not attached to a creature. Pay {2}{W} as a sorcery to unattach it.)
Enchant creature you control
Slopestrider's Chariot's rider gets +1/+1 and has double strike.

Counter target spell. If you control a Wizard, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Spend only mana of one color to cast this spell.

Reprise {3}{R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)
Hatsuo's Maneuver deals 1 damage to any target. Create a number of 1/1 red Warrior creature tokens equal to the damage dealt by this spell.

Lethal damage dealt to creatures is determined by their power rather than their toughness.

Whenever Conjured Stalker attacks, you may draw a card. If you do, discard a card.

Distribute three +1/+1 counters among any number of creatures you control.
Metamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Sleight (You may cast this spell as though it had flash if you pay {1} more to cast it.)
Enchant creature you don't control
Embody (Enchanted creature is a copy of this card except for its types.)

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)