msem-instigator

Whenever you cast an instant or sorcery spell, you may have Xenocrata's Fleet become a 4/4 Ship artifact creature with haste until end of turn.
Whenever Xenocrata's Fleet deals combat damage to an opponent, create that many 1/1 red Warrior creature tokens.

Nightwatch Rallier enters with X +1/+1 counters on it.
Other artifact creatures you control get +1/+1 for each +1/+1 counter on Nightwatch Rallier.

{T}: Add one mana of any color.
{3}, {T}, Sacrifice Coveted Heirloom: Draw a card.
Tap three untapped artifacts you control: Return Coveted Heirloom from your graveyard to the battlefield.

Each Merfolk and Wizard you control has “Whenever this creature attacks, abound.” (To abound, you may cast a spell that costs less than that creature from your hand without paying its mana cost.)

Whenever one or more cards are put into an opponent's graveyard from their hand or library, you may exile the top card of each player's library. Until your next turn, you may cast a card from among those exiled cards and you may spend mana as though it were mana of any type to cast that spell.

Deception {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Sacrifice a creature: Shinrei of the Ghosting Way can't be blocked this turn.
Whenever one or more Rogues you control deal combat damage to a player, return a creature card from your graveyard to your hand.

Menace, haste
Whenever another player casts a spell that targets Plasma Addict, that player gains control of Plasma Addict.

Deception {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Oshiruko Conspirator deals combat damage to a player, you may discard a Rogue card. If you do, search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Flying, haste
You may reveal each card you draw as you draw it. Whenever you reveal a creature card with mana value 1 or less this way, create a token that's a copy of it. That copy gains haste until end of turn.

[+2]: You may draw a card. If you don't, create a Treasure token. Repeat this process once.
[0]: Iviana deals X damage to each creature you don't control, where X is 2 plus twice the number of Dragons you control.
[–3]: Create a 5/5 red Dragon creature token with flying and haste.

{1}{U}{R}, {T}: Create a token that's a copy of another target creature, except it's an artifact in addition to its other types and has “Whenever this creature is dealt damage, destroy it.”

As long as it's your turn, planeswalkers you control are X/X creatures with indestructible that are still planeswalkers, where X is the number of loyalty counters on them.
Prevent all damage that would be dealt to planeswalkers you control during your turn.

Other creatures you control have haste.
Whenever Breach Titan enters or attacks, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
At the beginning of your end step, return another target creature you control to its owner's hand.

Trample
When Leyran Alpha enters, create two 2/2 green Wolf creature tokens with haste.
Whenever a creature you control deals damage to an opponent, put a +1/+1 counter on that creature.

Fardancer Liege's power and toughness are each equal to the number of colors of mana that lands you control could produce.

Flying
Synchronous Hellkite enters with a +1/+1 counter for each other artifact you control.
Sacrifice three artifacts: Return Synchronous Hellkite from your graveyard to the battlefield.

Gain control of target nonland permanent you don't control unless its controller has Bow or Burn deal X damage to them, where X is twice that permanent's mana value. If Bow or Burn was cast from a graveyard, repeat this process for each other nonland permanent they control.
Flashback {6}{R}{R}

Whenever you activate a loyalty ability of Xanigan, the Darkened Cloud, you get an emblem with exalted.
[+2]: Xanigan deals 2 damage to up to one target and you gain 2 life.
[–3]: You draw three cards and you lose 3 life.
[–7]: Xanigan becomes a 7/7 Demon creature with flying and indestructible that's still a planeswalker. Prevent all combat damage that would be dealt to her.

Exile target creature. Its controller may profit. (To profit, create a colorless Gold artifact token with “Sacrifice this artifact: Add one mana of any color.”)

At the beginning of your end step, put a -1/-1 counter on each creature you control.
[+1]: Create two 2/2 black Zombie creature tokens.
[0]: Whenever a creature dies this turn, you draw a card and you lose 1 life.
[–4]: Target opponent gets an emblem with “At the beginning of your end step, put a -1/-1 counter on each creature you control.”

Ammbradu Goliath gets -4/-4 for each card in your hand.

Whenever you cast a noncreature spell, you may put a progress counter on Wunderkind Devising.
[progress 1+] At the beginning of your upkeep, reveal the top three cards of your library. Put each artifact card from among them into your hand and the rest into your graveyard.
[progress 4+] Artifacts you control are artifact creatures with base power and toughness 5/5.
Artifacts you control are artifact creatures with base power and toughness 5/5.

Hexproof
Each creature you control with a card inscribed onto it has hexproof.

When Minister of Madness enters, create a 0/1 blue Weird creature token with flying.
{2}{U}, Sacrifice a creature: Search your library for an instant or sorcery card with mana value equal to 1 plus the sacrificed creature's mana value, exile that card, then shuffle. Then you may cast that card without paying its mana cost. Activate only as a sorcery.

Vigilance
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Champion of Destinies becomes renowned, you become the monarch.