msem-instigator

This creature has trample as long as there are four or more -1/-1 counters among creatures.
{3}{B}: Put a -1/-1 counter on target creature.

At the beginning of combat on your turn, target creature you control has base power and toughness 4/4 until end of turn.

Haste
When Collapsing Star Viper enters, you may tap target permanent with mana value X or less.
At the beginning of your upkeep, return Collapsing Star Viper to its owner's hand.

First strike

Whenever you draw a card, you may exile the top card of your library.
{3}{U}{U}, Sacrifice Collector of Memories: Shuffle your hand into your library, then put each card exiled with Collector of Memories into its owner's hand.

Creatures you control named Colocolo can't be blocked and have ward {2}.
{U}{U}: Put an inspiration counter on target creature. It's named Colocolo in addition to its other names for as long as it has an inspiration counter on it.

Trample
Spells and abilities your opponents control can't cause you to sacrifice Colossal Achievement.

Whenever one or more cards are put into your graveyard from your library, exile one of those cards.
Whenever Colossal Hermit deals combat damage to a player, you may cast a card exiled with it without paying its mana cost.

Trample
If one or more counters would be put on a permanent you control, three times that many counters are put on that permanent instead.

Lifelink
Partner with Imperator Valtasius (When this creature enters, target player may put Imperator Valtasius into their hand from their library, then shuffle.)
At the beginning of your upkeep, return target Soldier card from your graveyard to your hand.

When Commander of the Cavalry enters, you may search your library for a creature card with ride, reveal it, and put it into your hand. If you do, shuffle.
{X}, {T}: Put a creature card with ride and mana value X or less from your hand onto the battlefield transformed and attached to another target creature you control without a Steed attached to it.

Adorned — Commoners' Favored gets +2/+2 as long as it's equipped and/or enchanted.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Conchhorn Shinygrabber attacks, you may pay {1}. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{W}{U}{B}{R}{G}: Conchhorn Shinygrabber gets +3/+3 and gains lifelink until end of turn.

Spells you cast from exile cost {1} less to cast.

{T}: Conchspear Hunter deals 1 damage to any target. Activate only if you control three or more artifacts.

At the beginning of combat on your turn, you may exile a creature card from your graveyard. Then if a card exiled with Concoquo has flying, creatures you control gain flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Ferocious — At the beginning of your first main phase, if you control a creature with power 4 or greater, add {R}.

Vigilance
Conflict Capturer gets +2/+0 as long as a permanent you controlled left the battlefield this turn.

When Conjured Shade dies, target creature you don't control gets -1/-1 until end of turn.

Whenever you cast an Aura spell, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)

Deathtouch
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.)

When Contagious Ghoul dies, target creature an opponent controls gets -1/-1 until end of turn.
Foreshadow {2}{B} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

When Contagious Host dies, each player loses 1 life.
Revive {2}{B} ({2}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Flash
Whenever you draw a card during an opponent's turn, you get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)