msem-instigator

({T}: Add {W} or {U}.)
Bustling Harbor enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Bwema, the Ruthless enters with your choice of two different counters on it from among menace, first strike, vigilance, and lifelink.

Haste
Sacrifice another creature: Bygone Aristocrat gains indestructible until end of turn.

Equipped creature gets +1/+2.
At the beginning of your end step, if Bygone Blade isn't attached to a creature, you get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)
Equip {2}

Menace, haste
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

Haste
Revive {3}{R} ({3}{R}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature you don't control blocks, Cadalon Chemist deals 1 damage to that creature.

Whenever you investigate for the first time each turn, investigate an additional time.
{T}, Sacrifice an artifact: Cadalon Inspector deals 2 damage to any target.

Choose one or both —
• Put target detained creature on top of its owner's library.
• Detain target creature. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Return up to two target creatures and/or artifacts to their owners' hands. For each permanent returned to its owner's hand this way, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Flying
When Calamity Harbinger enters, it deals 4 damage to up to one target creature or planeswalker.

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.

Target creature or planeswalker you control explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 or loyalty counter on that permanent, then you may put that card into your graveyard.)

({T}: Add {W}.)
As Calcified Dunes enters, you may pay 1 life. If you don't, Calcified Dunes enters tapped.

Calciform Wastes enters tapped. When it does, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this, then you may put that card into your graveyard.)
{T}: Add {W}.
{2}{W}{W}: Calciform Wastes becomes a Turtle creature. (This effect lasts indefinitely.)

Search your library, graveyard, and/or the command zone for a legendary creature card, reveal it, and put it into your hand. If you search your library this way, shuffle.

Return up to one target noncreature, nonland card from your graveyard to your hand.
Call of the Huma deals 4 damage to any target.
Exile Call of the Huma.

Each player sacrifices a creature. Then return a creature card with mana value 3 or less from your graveyard to the battlefield.

Create a 1/1 colorless Construct Actor creature token. Put a +1/+1 counter on it if you control another Construct.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

When Callous Renegade enters, you may return target Rebel creature card with mana value 4 or less from your graveyard to the battlefield. It gains haste until end of turn.

Battalion — Whenever Callous Trainer and at least two other creatures attack, create a 1/1 white Warrior creature token that's tapped and attacking.

When Callow Survivors enters, you may return target artifact or enchantment card with mana value 3 or less from your graveyard to the battlefield.

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a card from the archived library, put the top card of your main library on the bottom of the archived library.
{G}: Exchange a card from the archived library with a card from your hand.

When Campaign Recruiter enters, you may search your library for a creature card with first strike, double strike, flying, improve, lifelink, melee, or vigilance, reveal it, put it into your hand, then shuffle.

You may cast this spell with no targets for {2}{R}. If you do, as it resolves, create a 1/1 red Hound creature token, then attach Canine Acumen to that token.
Enchant creature
Enchanted creature gets +2/+0 and has first strike.