msem-instigator

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

I — Exile target creature an opponent controls until The Banishment of Seh'a leaves the battlefield.
II — Exile up to three cards from target opponent's graveyard.
III — You gain life equal to the number of cards in exile.

Creatures you control get +2/+0 until end of turn.

Deathtouch, lifelink
At the beginning of combat on your turn, for each creature your opponents control, you may tap an untapped creature you control. If you do, those creatures fight each other.

When Thespian's Page enters, return target instant or sorcery card from your graveyard to your hand.

When Threshing Sundew enters, merge up to one target creature card in your graveyard under it. Threshing Sundew has that card's abilities.
When Threshing Sundew dies, return all other cards merged with it to their owner's hand.

Haste
At the beginning of combat on your turn, create two nonlegendary token copies of Thrice-Clawed Troika. Then for each creature token created this way, create token copies of each permanent attached to Thrice-Clawed Troika and attach them to that creature token. Exile all tokens created this way at end of combat.

Each player sacrifices a creature with mana value X or greater.
Return up to one target creature card with mana value X or less from your graveyard to the battlefield.

Return target creature card from your graveyard to the battlefield.

Each player may search their library for a creature card, reveal it, and put it into their hand. Then each player who searched their library this way shuffles it.

Creatures you control gain double strike until end of turn. Whenever a creature you control deals combat damage this turn, put a +1/+1 counter on it.

Exile target creature. Its controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield, then shuffles all other cards revealed this way into their library.

Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Mill four cards, then return any number of creature cards with total mana value 4 or less from your graveyard to the battlefield.

Menace
Unveil {3}{B}{R} ({3}{B}{R}: Transform this. Unveil only as a sorcery.)

Flash
Deathtouch

Other legendary creatures you control get +1/+1.
At the beginning of your upkeep, you may search your library for a legendary card, reveal that card, and put it into your hand. If you do, you skip your draw step this turn and shuffle.

Flying
Venerable Skyblade can't attack unless defending player controls a creature with flying.
When Venerable Skyblade enters, you may put a +1/+1 counter on target creature you control.

Draw two cards, then discard two cards.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Whenever Warhound Shuja attacks, look at the top three cards of your library. You may put a creature card with mana value less than or equal to Shuja's power from among them onto the battlefield tapped and attacking. Put the rest on the bottom of your library in any order.

Whenever Wavering Sorcerer attacks, you may switch its power and toughness until end of turn.
Unveil {3}{U}{R} ({3}{U}{R}: Transform this. Unveil only as a sorcery.)

At the beginning of your upkeep, each player draws a card.

[+1]: Until your next turn, when up to one target creature dies, return a creature card with lesser mana value from your graveyard to the battlefield tapped.
[–1]: Target player discards a card. When they do, return a card with equal mana value from your graveyard to your hand.
[–2]: You may sacrifice a creature. When you do, exile target nonland permanent.

{2}{R/G}: Wildershrine Warden gets +2/+2 until end of turn. You may have it assign its combat damage this turn as though it weren't blocked. Activate only once each turn.

At the beginning of each player's upkeep, you may exile target permanent that player controls. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step.