msem-instigator

Create three 1/1 white Soldier creature tokens. If you control an attacking creature, they're tapped and attacking. If you control a blocking creature, they're blocking target attacking creature.
Quickdraw {2}{W} (When a creature you control blocks or becomes blocked, you may cast this for {2}{W}.)

Flying
Whenever Herald of Shadow attacks, another target creature can't be blocked this turn.
Whenever a creature you control deals combat damage to an opponent, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Whenever a creature you control attacks alone, untap all lands you control.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{1}, Discard two cards: Unlock Cryptic Fragment. If the revealed card is a basic land card, put it into your hand.

Whenever Deceitful Soul becomes blocked by one or more creatures, it gets +2/+0 until end of turn.

Return target instant or sorcery card from your graveyard to the battlefield face down. It gains metamorph. The metamorph cost is equal to its mana cost. (It's a 2/2 creature. Turn it face up and cast it at any time for its metamorph cost.)

Enchant creature
Enchanted creature gets +2/+2, can't be the target of spells or abilities you don't control unless their controller controls no untapped lands, and can't be blocked unless all creatures defending player controls that are able to block it do so.

When Escorted Ambassador enters, create two 1/1 white Robot Soldier artifact creature tokens.
Whenever a nonland, nontoken permanent enters, exile it unless it was the first to enter under its controller's control this turn.

Hexproof
Crossworld Wanderer gets +1/+1 for each differently named land you control.

Prowess
{3}{R}, Sacrifice Goblin Experimenter: Return target sorcery card from your graveyard to your hand.

Flying
Whenever Hao'Tai deals combat damage to a player, that player exiles the top five cards of their library and separates them into two piles. Put an ember counter on each card in the pile of your choice. You may play cards from exile with ember counters for as long as they remain exiled.

Rugged Highlands enters tapped.
When Rugged Highlands enters, you gain 1 life.
{T}: Add {R} or {G}.

As Calamity Apparition enters, choose fade or linger.
When Calamity Apparition dies,
• Fade — You gain 2 life and scry 2.
• Linger — Put a +1/+1 counter on target creature you control.

Whenever a land you control enters, you may have target creature get +1/+0 and gain first strike until end of turn.

When Journey through Moranai enters, draw a card, then choose a creature card name.
Creatures you control with the chosen name have haste and “{R}: This creature gets +1/+0 until end of turn.”

Whenever Ming Fleet Privateer attacks, put a menace counter on target creature in its pack. (Two or more creatures you control with equal power are in a pack.)

Glitch {3}{W} (Remove one [restriction] for each time you pay the glitch cost.)
Exile target nonland permanent. [Return it to the battlefield under its owner's control at the beginning of the next end step.]

Vanishing 5 (This permanent enters with five time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Players play with the top card of their libraries revealed.
Whenever a time counter is removed from Precarious Ledgers, you may have target player mill a card.

Trample
Deploy 3 (As this enters, you may tap any number of other creatures you control with total power 3 or more.)
When Coalition Grenadier enters deployed, it deals 4 damage to target creature you don't control.

Harvest (You may tap any number of creatures you control as you cast this spell. If you do, reduce this spell's mana cost by their total power.)
Draw three cards.

If another creature with a +1/+1 counter on it you control would die, instead remove a counter from it. If you do, it phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Choose a creature type. Reveal cards from the top of your library until you reveal a card of the chosen type. Put that card into your hand and the rest on the bottom of your library in a random order.

Engulf in Flames deals 1 damage to target player and each of up to three target creatures that player controls. Those creatures can't block this turn.

Advance {4}{R} (Cast this for {4}{R} to advance it as it enters. {4}{R}: Advance this as a sorcery.)
Whenever Intruder Drone advances, exile the top card of your library. You may cast a spell exiled with Intruder Drone with mana value 3 or less without paying its mana cost.

{T}, Pay 1 life: Add {U} or {R}.
{2}, {T}, Sacrifice Lamplit Thoroughfare and another permanent: Draw a card. Activate only during your turn.