msem-instigator

When Astute Sceneweaver enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Spires of Caulte enters tapped.
{T}: Add {B} or {R}.
{B}{R}: Until end of turn, Spires of Caulte becomes a 3/2 black and red Construct creature with with menace and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Enchant creature
Enchanted creature gets +2/+2 and has flying and haste.
When enchanted creature dies, return it to the battlefield under its owner's control.

{T}, Sacrifice Skeletal Oasis: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Up to two target creatures each get +X/+X until end of turn. They must be blocked this turn if able.

Enchant opponent
Spells you cast that target enchanted player cost {2} less to cast.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Danaj Rising enters, target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 1 life.

Return target creature card from your graveyard to the battlefield, then search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever two or more creatures you control deal combat damage to a player, add a quest counter.
1, 2 — Create a 2/1 black and red Cat Pirate creature token with menace.
3 — Create a colorless artifact token named Motherlode with “{T}: Add two mana of any one color” and
“{3}, {T}, Discard your hand: Draw two cards.”

Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters.)
Snakes you control get +1/+1 and have poisonous 1. (Multiple instances of poisonous trigger separately.)

When Scorpid Sniper enters, you may have target creature get -1/-1 until end of turn.

First mate—At least half the cards in your starting deck are lands. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Trample
{1}, Discard a land card: Put a +1/+1 counter on Alvarez. He deals 1 damage to any target.

{2}, Exile Cranial Archive: Target player shuffles their graveyard into their library. Draw a card.

When Bjarndyr Outfitter enters, arm up to two target creatures you control. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Creatures you control gain haste and trample until end of turn.
Draw a card.

This spell costs {2} less to cast if you control a transformed permanent.
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

If you cast this spell from exile, it deals 7 damage to target creature. Otherwise, return Fortunous Flames to your hand, then reveal a card from your hand at random.
Prophecy {R} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Whenever a nontoken creature you control dies, create a 1/1 black Worm creature token.
Sacrifice Fertile Grave: Create a 1/1 black Worm creature token.

When Flameform Amalgam enters, you may return target instant or sorcery card from your graveyard to your hand.
Recite {4}{R} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Whenever a player casts an instant or sorcery spell from their hand, you may exile that card as it resolves instead of putting it anywhere else.
Whenever Skill Sketcher attacks, you may cast a card exiled with it. That spell costs {X} less to cast, where X is Skill Sketcher's power.

Sacrifice Moonlight Agent: Blocking creatures gain first strike until end of turn.

When Viridian Townships enters, create two Idol tokens. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
{2}, Sacrifice an Idol: Draw a card.
{2}, Sacrifice an Idol: You gain 3 life.

When you cast Senaturian Centurion, reveal cards from the top of your library until you reveal a creature card with mana value 2 or less. Copy that card, then put the revealed card into your hand. You may cast the copy without paying its mana cost. Put the revealed cards on the bottom of your library in a random order.