msem-instigator

(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.

Counter target enchantment, instant, or sorcery spell. (Then exile this card. You may cast the creature later from exile.)

Put a +1/+1 counter on up to one target creature. (Then exile this card. You may play the land later from exile.)

Naxila, the Blessed City enters tapped.
When Naxila, the Blessed City enters, you gain 2 life and draw two cards.
{T}: Add {C}{C}.

Create a 1/1 white and black Badger Cleric creature token with lifelink. (Then exile this card. You may cast the creature later from exile.)

Nightshaper's Domain enters tapped.
{T}: Add {B}.

Flying
At the beginning of your upkeep, mill seven cards, then you may cast an instant or sorcery card from your graveyard. If that spell would be put into your graveyard, exile it instead.
If you would draw a card while your library has no cards in it, you win the game instead.

Indestructible
When this creature transforms into Ninhasir, God of Creation, discard all the cards in your hand, then draw that many cards plus one.
Whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.

Tap target creature. That creature doesn't untap during its controller's next untap step.

Target attacking creature gets +3/+1 and gains trample until end of turn. (Then exile this card. You may cast the creature later from exile.)

At the beginning of your end step, 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.)

Enchant planeswalker
Enchanted planeswalker has “+2: Draw two cards, then put a card from your hand on the bottom of your library.”

Target creature you control gains haste until end of turn. Return it to its owner's hand at the beginning of the next end step.

Search your library for a land card, reveal it, then shuffle and put that card on top. (Then exile this card. You may play the land later from exile.)

Whenever Optimistic Chronicler deals damage to a player or noncreature permanent, surveil 1, then draw a card.

All creatures able to block Orphaned Nuckalavee do so.

At the beginning of your upkeep, scry 1, then you gain 1 life.

Enchant player
At the beginning of your upkeep, enchanted player loses 1 life.

Whenever Overgrowth Host attacks, germinate. Then creatures you control that are Saprolings or have counters on them gain trample until end of turn.
Saprolings you control get +1/+1.

Whenever you sacrifice a permanent, Overseer of Armies deals 1 damage to each opponent and each battle they protect.

(Transform this if it's not attached to a creature. Pay {G} as a sorcery to unattach it.)
Enchant creature you control
When this permanent transforms into Packbond Mount, move all +1/+1 counters from it to its rider.
Packbond Mount's rider gets +1/+1.
{2}{G}: Put a +1/+1 counter on Packbond Mount's rider.

Enchant creature
Enchanted creature gets +1/+1 and has “At the beginning of each end step, you gain 1 life.”

Create two tapped Treasure tokens. (Then exile this card. You may cast the creature later from exile.)