msem-instigator

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Cheerful Generator has three or more +1/+1 counters on it, remove them all and transform it.

Whenever another creature named Chef's Apprentice you control enters, target player mills three cards.

{X}, {T}, Sacrifice Chemical Grenade: Up to X target creatures each get -1/-1 until end of turn.

Flying, haste
Whenever Cheng attacks, look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. If it's a Dragon, put it onto the battlefield tapped and attacking instead. Put the rest on the bottom of your library in a random order.

Equipped creature gets +2/+1.
Equipped creature has first strike as long as it's attacking.
Whenever a Knight or Soldier you control attacks, you may attach Chevalier's Lance to it.
Equip {3}

Each player sacrifices X lands. Chew the Scenery deals X damage to each creature.

Whenever a player casts an instant or sorcery spell that targets exactly one creature they don't control, you may copy that spell. If you do, you may choose new targets for the copy.

[+1]: Return up to one target Aura card from a graveyard or on the battlefield to its owner's hand.
[–2]: Sacrifice an enchantment. If you do, return target enchantment card from your graveyard to the battlefield.
[–6]: Draw three cards. Until end of turn, you may cast enchantment spells without paying their mana costs.

First strike
As long as it's your turn, other creatures you control get +1/+0.

Chigau Market Outskirts enters tapped. When it does, choose a creature card name.
{T}: Add {B}.
{1}, {T}, Sacrifice Chigau Market Outskirts: You may cast a creature spell with the chosen name from your graveyard this turn.

When Chiheisen, Terrace of Serenity enters, draw a card, then choose a creature card name.
Spells you cast with the chosen name cost {2} less to cast.

{T}: Add {C}.
{1}, {T}, Sacrifice Chikyu League Arena: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Enchant creature
When Child of the Pack enters, create a 2/2 green Wolf creature token.
Enchanted creature gets +1/+1 for each Wolf you control.

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

Reach
Spirited (When this creature enters, you may activate one of its activated abilities without paying its costs.)
{3}{G}: Exile up to one target card from a graveyard. Scry 1.

{1}{G}, Discard a card: Target land you control becomes a 3/3 Elemental creature. It's still a land. Exile the top card of your library face down.
Whenever a land creature you control deals combat damage to a player, put a card exiled with Children of Gos into your hand.

Children of the Void has hexproof as long as it's your turn.
Children of the Void can't attack or block unless you reappropriate (exile exactly two cards from your hand and/or graveyard).

Harmony — Tap target creature. That creature doesn't untap during its controller's next untap step.
When Chilling Musician enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
Spells you cast that share a type with the card Chillwhisper Witch engorged cost {1} less to cast.

Whenever another creature you control dies, target player loses 1 life and you gain 1 life.

When Chimera Graft dies, manifest the bottom card of your library. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Equipped creature gets +4/+3.
Equip—{2}, Put a -1/-1 counter on a creature you control.

Trample
Whenever a lore counter is put on a Saga you control, Chimperial Guard gets +2/+2 until end of turn.

Chiseled Cliffside enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Concord — Whenever Chitinborn Sentry attacks, if there are four or more card types among permanents you control, prevent all damage that would be dealt to target attacking creature this turn.