msem-instigator

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 may put that card into your graveyard.)
{T}: Add {W}.
{2}{W}{W}: Calciform Wastes becomes a Turtle creature. (This effect lasts indefinitely.)

Whenever Caldera Crawlers attacks, you may sacrifice a land or exile a land card from your graveyard. If you do, target creature gets +1/+1 and gains menace until end of turn.

Deathtouch
Once each turn, when another nontoken creature you control enters, you may sacrifice it. If you do, create a token that's a copy of it except it's a green Dryad in addition to its other types.

Calfu, Greatest Toqui is all colors.
As long as there are five or more basic land types among lands you control, other creatures you control get +2/+1 and have vigilance.
When Calfu dies, you may search your library for a card named Heart of Carü Mapu, put it onto the battlefield, then shuffle.

You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead.

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.

{W}{B}, Exile a creature card from your graveyard: Search your library for a creature card and put that card into your graveyard, then shuffle.
{3}{B}{R}, Discard a card: Return target creature card from your graveyard onto the battlefield. It gains haste. Exile it at the beginning of the next end step. If that creature would leave the battlefield, exile it instead of putting it anywhere else.

Call of the Abyss deals 3 damage to any target and you gain 3 life.

Target player mills three cards for each artifact you control.

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.

Recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
Armies you control gain trample until end of turn.

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.”)

Exile target nontoken creature. That creature's controller creates X 1/1 red and white Warrior creature tokens, where X is that creature's mana value.

Sacrifice a permanent, then draw cards equal to its mana value.
You may put a permanent card from your hand onto the battlefield if its mana value is less than or equal to the number of cards in your hand.

Destroy up to one target creature with flying or enchantment. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

{1}{G}{G}, Sacrifice a creature: Search your library for a creature card with mana value X or less, where X is 1 plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle. Activate only as a sorcery.

First strike
Whenever you make first contact, Callous Conduit deals 1 damage to target player or planeswalker. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

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.

Ascend—{W}{B}, Discard a card, Sacrifice a creature, Exile a creature card from your graveyard. ({W}{B}, Discard a card, Sacrifice a creature, Exile a creature card from your graveyard: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

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.