msem-instigator

Whenever you cast a spell that's white, blue, black, or green, create a 1/1 white Soldier creature token.

Put a +1/+1 counter on target creature. It can't be blocked this turn.(Cast a copy of this spell once while this creature is on the battlefield.)

If Madame Beatrice would leave the battlefield, exile her instead.
Whenever one or more creatures you control deal combat damage to a player, that player reveals their hand. You may cast a card from their hand without paying its mana cost.

Search your library for an Equipment card, reveal it, put it into your hand, then shuffle. (Then exile this card. You may cast the creature later from exile.)

Enchant creature
Enchanted creature has first strike and trample.

Flying, lifelink
Your opponents can't search libraries.
{B}, Pay 2 life, Discard a card: Search your library for a card, then shuffle and put that card on top.

Whenever Marshback Knights becomes the target of a spell or ability an opponent controls, counter it unless they pay {3}.
{1}{U}: Marshback Knights gains flying until end of turn.

Master Assassin can't be blocked by creatures with odd mana values. (Zero is even. This creature's mana value is 2.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Master Assassin. You may have it phase out.

Whenever an Actor you control becomes untapped, you may discard a card. If you do, draw a card.

Enchant creature
Enchanted creature has defender.

First strike
Mauling Mother gets +1/+1 for each other creature you control.

Whenever you condemn a creature, each opponent sacrifices a creature.
{4}{B}: Judge target creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

Flying
Whenever you cast a spell, draw a card, then put a +1/+1 counter on Maven of Perspective.

Your opponents can't gain life.
If a source you control would deal damage to an opponent, it deals double that damage instead.
At the beginning of your end step, if Mayhem Tandem didn't attack this turn, transform it.

Lifelink
If a source would deal damage to a player, you may prevent X of that damage, where X is the number of +1/+1 counters on Mending Caretaker.

Enchant player
Enchanted player's maximum hand size is reduced by two.

Exile target creature. (Then exile this card. You may cast the creature later from exile.)

Players play with the top card of their libraries revealed.
[+2]: Target player mills a card. Draw a card.
[+1]: Create a 1/1 blue Illusion creature token with “This gets +1/+1 for each other Illusion you control.”
[–4]: Return target creature card from a graveyard to the battlefield under your control. It's an Illusion in addition to its other types.

You may play an additional land on each of your turns.
Landfall — Whenever a land you control enters, draw a card.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever Mistress of Frost extorts a spell, you may tap target artifact or creature.

Prowess, trample
When this creature transforms into Mortal Frame, add {R}{R}{R}.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

(Transform this if it's not attached to a creature. Pay {1}{W} as a sorcery to unattach it.)
Enchant creature you control
Mount of Heroes's rider gets +2/+1.
Sacrifice Mount of Heroes: Counter target spell that targets you or Mount of Heroes's rider.

(Transform this if it's not attached to a creature. Pay {3}{R}{R} as a sorcery to unattach it.)
Enchant creature you control
Mount of the Order's rider gets +5/+4.
{2}{R}: Target creature can't block Mount of the Order's rider this turn.

Menace
At the beginning of your end step, Mountain Tyrant deals 1 damage to each creature you don't control.