msem-instigator

Vigilance, ward {1}
{T}: Add one mana of any color. If that mana is spent on a creature spell, it enters with an additional +1/+1 counter on it.

Target player mills seven cards.
Inscribe {3}{U}{B} ({3}{U}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Enchant creature with flying
Enchanted creature can't attack or block, and it loses all abilities other than flying.

({T}: Add {R}.)
Rousing Rubble enters tapped.
Double strike
{2}{R}{R}: Rousing Rubble becomes a creature in addition to its other types until end of turn.

{2}: Carven Guardian gains reach until end of turn.

Starting with the next opponent in turn order, each player sacrifices a permanent. Repeat this process until the total mana value of all permanents sacrificed this way is 13 or greater, or until thirteen or more permanents have been sacrificed this way, or until there are no nonland permanents on the battlefield, whichever happens first. Exile Utter Pandemonium.

When Grim Procession enters, create two 2/2 black Zombie creature tokens.
{2}{B}: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Target player reveals their hand. You choose a nonland card from it. That player discards that card if it has mana value 2 or less or this spell was foretold.
Foretell {B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.
{3}{W}{U}: Tap target creature and put a +1/+1 counter on Solitary Guardian.

Colossal 2—{4}{B}{B} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {4}{B}{B} as a sorcery: Put two +1/+1 counters on it if it has none.)
Menace
When Wretched Catoblepas's colossal ability puts one or more counters on it, each opponent sacrifices a creature.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

{T}: Add {C} and one mana of any color.

Forestheart Elemental enters with a +1/+1 counter on it for each land you control.

Each creature gets -X/-X until end of turn. Destroy each artifact and enchantment with mana value X or less.

(Choose only one work as a sorcery to add its ability.)
When Those Lost to the Waves enters, search your library for an artifact card with mana value 3 or less, reveal it, put it into your hand, then shuffle.
{1}{W}: Fight the Current
Equipped creatures you control get +1/+1.
{3}{U}: Soul of the Sea
At the beginning of combat on your turn, you may have target noncreature artifact become a 3/3 artifact creature until end of turn.

When Twilight Vigil enters, scry 2, then put a night counter on it.
Death knell — Put a night counter on Twilight Vigil. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Sacrifice Twilight Vigil: For each night counter on it, you gain 1 life and trigger up to one death knell of a permanent you control.

I — Exile the top card of your library face down.
II — Exile any number of cards from your hand face down.
III — Calamity of Yore deals damage to target creature or planeswalker equal to the number of cards you own in exile. Return all cards exiled with Calamity of Yore to their owners' hands.

Prowess
Gilded Gunman gets +1/+1 as long as you control an artifact.

Trample
When Magmatic Ravager enters, two target lands you control don't untap during your next untap step.

Prowess, haste
You may spend mana as though it were mana of any color to cast noncreature spells with mana value 3 or less.

When Defiler of Farmsteads enters, each opponent loses 2 life and you gain 2 life.

Destroy target creature, enchantment, or planeswalker. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Other creatures you control have haste.
Whenever Breach Titan enters or attacks, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
At the beginning of your end step, return another target creature you control to its owner's hand.

Once each turn, when you cast an instant or sorcery spell, you may exile the top two cards of your library if you cast it for its showcase cost, otherwise, look at the top two cards of your library, then put one on the bottom of your library and exile the other. You may play cards exiled this way until you exile one or more other cards with For the Court of the Queen.

This spell costs {2} less to cast if there's a storied card in your graveyard. (Enchantments and legendary cards are storied.)
Search your library for a storied card, reveal it, put it into your hand, then shuffle.