msem-instigator

Target tapped creature gets -3/-3 until end of turn.

Non-Actor creatures can't block this turn.

{T}, Pay 1 life: Add {R} or {W}.
{1}, {T}, Sacrifice Backstage Rooms: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

At the beginning of your end step, create a 1/1 white Soldier creature token.

Exile target creature or planeswalker. You gain 4 life.

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice Bag of Holding: Return all cards exiled with Bag of Holding to their owner's hand.

Scry X, then purge X times. You lose X life. (To purge, exile two cards that share a type from graveyards. If you do, draw a card.)

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Choose two —
• Destroy up to one target enchantment.
• Exile up to one target card from a graveyard.
• You gain 4 life.
Cycling {1}{W} ({1}{W}, Discard this card: Draw a card.)

As an additional cost to cast this spell, discard your hand.
Purge four times, then you gain 1 life for each card in exile. (Exile two cards that share a type from graveyards. If you do, draw a card.)

[+1]: Discard a card. If you do, up to one target player gains 5 life.
[–3]: Discard a card. You draw X cards and you lose X life, where X is that card's mana value.
[–7]: Exile your hand, then put all cards from your graveyard into your hand and all cards exiled this way into your graveyard.

[+1]: Exile up to two target cards from graveyards. You gain 3 life.
[–2]: Exile target artifact, enchantment, or nonbasic land.
[–7]: You get an emblem with “At the beginning of your upkeep, exile target noncreature permanent.”

When Bal's Descent enters, each player sacrifices a creature, discards two cards, and mills three cards.
{1}{B}{B}: Transform Bal's Descent. Activate only if your fealty to Swamps is five or greater.

Target creature gets +1/+0 and can't be blocked this turn.
Showcase {2}{U} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

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.

Equipped creature gets +3/+0 and has vigilance.
Equip {3}

Whenever equipped creature attacks, it gains deathtouch until end of turn.
Sacrifice Bandit's Dagger: Target player dealt damage by equipped creature this turn reveals their hand. You choose a nonland card from it. That player discards that card.
Equip {2}

Enchant player
At the beginning of each end step, create X 1/1 green Snake creature tokens, where X is the amount of life enchanted player lost this turn.

Destroy target face-up creature.

As an additional cost to cast this spell, sacrifice a creature.
All creatures get -X/-X until end of turn, where X is the sacrificed creature's power.

Exile target creature or planeswalker and all other creatures its controller controls with the same name as that permanent. Search its controller's graveyard, hand, and library for any number of nonland cards with the same name as that permanent and exile them. Then that player shuffles.

Destroy all creatures. Exile all graveyards.

Counter target planeswalker spell.
Draw a card.

Exile up to three target cards from graveyards. (Then exile this card. You may cast the creature later from exile.)

Gain control of target artifact or creature until end of turn. Untap it. If it's a creature, it gains haste until end of turn and up to one target creature can't block it this turn.