msem-instigator

At the beginning of combat on your turn, if there are five or more creature types among creatures you control, creatures you control get +2/+0 and gain menace until end of turn.

{T}: Add {C}.
{3}: Mill two cards, then return Midnight Keep from your graveyard to the battlefield tapped.

{1}{G}, Discard a card: Target land you control becomes a 3/3 Elemental creature. It's still a land. Exile the top card of your library face down.
Whenever a land creature you control deals combat damage to a player, put a card exiled with Children of Gos into your hand.

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Return target creature card from your graveyard to the battlefield. Then if you control a creature with toughness 4 or greater, create a 1/1 black Bat creature token with flying and “This creature can't block.”

Target opponent may have you draw X cards. If they don't, reveal the top X cards of your library. Hell's Verdict deals damage to that player equal to the total mana value of cards revealed this way.

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

You may put a creature or planeswalker card from your hand onto the battlefield. It gains haste. Sacrifice it at the beginning of the next end step. Whenever an ability of that permanent is activated this turn, you may copy that ability. You may choose new targets for the copy.

When Occult Mastermind enters, create two 2/2 black Zombie creature tokens. When Occult Mastermind is no longer on the battlefield, sacrifice two Zombies.

When Rat King enters, create two 1/1 black Rat creature tokens with “This creature can't block.”
Whenever Rat King or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Choose one —
• Destroy target artifact.
• Metal Munch deals 1 damage to each of up to two targets.

If a nontoken creature you don't control would die, exile it instead.
Once each turn, you may cast a card exiled with Accursed Existence.

Trample
Phoberos Ragehorn has haste as long as you control another Minotaur.
Whenever Phoberos Ragehorn attacks, each player discards a card.

{1}{R/W}: Untap Blade of the Long Night.

Haste
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Bolstered Guardian. It loses this ability and gains “Whenever this attacks, it deals 2 damage to each of up to two targets.”

When Flame Juggler dies, it deals 3 damage to each opponent.

Batrest, Fellor Leader gets +1/+1 for each Equipment attached to it.
When Batrest enters, create Astrina, Forged for Glory, a legendary colorless Equipment artifact token with “Equipped creature gets +4/+4 and has first strike and lifelink” and equip {4}. Attach it to Batrest.

Repurposed Construct enters tapped.
{T}: Add {B} or {G}.
{B}{G}, {T}, Sacrifice Repurposed Construct: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Legacy (You may play this side of this card only from your graveyard. Exile it if it would leave the battlefield or not resolve.)
At the beginning of your end step, you may search your library for a creature card, reveal it, put it into your hand, then shuffle.

Choose two or four —
• Return target nonland permanent to its owner's hand.
• Each player sacrifices a creature.
• Each player sacrifices a noncreature, nonland permanent.
• Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

Soul of Misery gets +1/+1 as long as you control a Swamp.
{4}{B}: Target player discards a card. Activate only as a sorcery.

At the beginning of each player's upkeep, that player may sacrifice a creature. If they don't, they discard a card.

When Suitor of the Glade enters, put two +1/+1 counters on target creature you control. It gains vigilance until end of turn.

As Grim Bastion enters, you may pay 2 life. If you don't, Grim Bastion enters tapped.
{T}, Sacrifice Grim Bastion: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

{1}{R}{G}: Feral Exemplar gets +2/+2 until end of turn. Activate only once each turn.
Ferocious — Whenever a creature you control with power 4 or greater attacks, that creature gets +X/+X until end of turn, where X is its power.