msem-instigator

Draw three cards. Discard your hand at the beginning of the next end step.

When Isle Conservator enters, if you control a legendary creature, submerge target creature an opponent controls. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Whenever Bound Apparition becomes the target of a spell or ability, put a -1/-1 counter on it.

Return target nonland permanent to its owner's hand.
Exile target nonland permanent you control, then return it to the battlefield under your control.

Return up to two target instant and/or sorcery cards from your graveyard to your hand. Exile Intense Revelation.

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

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Whenever you cast a spell, Daemonspawn deals 1 damage to each cursed opponent.

Flying, haste
Whenever The Branded Usurper attacks, it deals 2 damage to any target.
If you would lose the game, instead exile The Branded Usurper. Your life total becomes 0. Until an opponent's next turn, you can't lose the game and you can't gain life. Take an extra turn after this one.

(Choose only one work as a sorcery to add its ability.)
When The Art of War enters, if a source you control would deal damage this turn, it deals double that damage instead.
{2}{R}{R}: Laying Plans
Whenever you attack for the first time each turn, untap each creature you control. After this phase, there is an additional combat phase.
{2}{R}{R}: Waging War
Whenever a creature you control attacks, create a token that's a copy of it that's tapped and attacking, except the token isn't legendary. Exile those tokens at end of combat.

First strike
When Imperial Dragoon enters, target creature gets +2/+0 until end of turn.

{G}, Tap an untapped Nymph you control: Overgrown Beast gets +2/+2 until end of turn.

Creatures you control get +1/+1 and gain flying and lifelink until end of turn.

Put target spell or nonland permanent on top of its owner's library.

Converge — Precursor Sentinel enters with a +1/+1 counter on it for each color of mana spent to cast it.
Remove a +1/+1 counter from Precursor Sentinel: It deals 1 damage to any target.

When Thallid Cultivator dies, mill four cards. Return a creature card milled this way to your hand.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Sacrifice Bonetooth Darter: Counter target instant, planeswalker, or sorcery spell unless its controller pays {1}.

Flash

When Loyal Retriever dies, search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.
Foreshadow {5}{W} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Hostile Habitat deals 2 damage to each creature.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

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.)
Trample

{T}: Add {C}.
{T}: Choose a color from among permanents you control. Add one mana of that color.

Attacking creatures get +2/+0 until end of turn. If you control a legendary creature, those creatures also gain first strike until end of turn.

At the beginning of your upkeep, you win the game if the total mana value of permanents you control is exactly 21. If it's more than 21, sacrifice Gambling Table and all Card tokens you control. Otherwise, create a colorless Card artifact token with mana cost {2} and “{2}, Sacrifice this artifact: Draw a card.”

Investigate ten times. (Create ten colorless Clue artifact tokens with “{2}, Sacrifice this artifact: Draw a card.”)

For each nonland token you control, create a token that's a copy of it.