msem-instigator

{U}, Discard a card: Exile target instant or sorcery card from your graveyard. If you do, copy it. You may cast the copy.
{B}, Discard a card: Exile target creature card from your graveyard and pay its mana cost. If you do, create a token that's a copy of it. Activate only as a sorcery.

Equipped creature gets +1/+1.
Whenever equipped creature deals combat damage to a player or noncreature permanent, create a Treasure token.
Equip {1}

This creature can't be blocked by creatures with power less than the number of creatures you control.
{3}{G}: Create a 1/1 white Peasant creature token.

When Atlas of Worlds enters, search your library for any number of land cards with different names and exile them, then shuffle.
You may play lands exiled with Atlas of Worlds.

Trample
Risti Assault Squadron can't attack unless all other creatures you control also attack. (It can attack if it's the only creature you control.)

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

Reprise {3}{R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)
Hatsuo's Maneuver deals 1 damage to any target. Create a number of 1/1 red Warrior creature tokens equal to the damage dealt by this spell.

Trample
If one or more counters would be put on a permanent you control, three times that many counters are put on that permanent instead.

Creatures can't attack you unless their controller pays {3} for each of those creatures.

Lionize {2}{R} ({2}{R}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following abilities until end of turn. You may cast this card on a later turn from exile.)
Trample
This creature gets +3/+0 as long as it's attacking.

Flying
Menagerie — When Old-Rune Watcher enters, if there are five or more creature types among creatures you control, draw a card.

{T}: Add {C}.
Satrapies you control have “{1}, {T}: Add one mana of any color.”

When Tamer of the Ton dies, create a 4/4 green Chimera creature token.

Bulwark — When Tharanos' Legion enters, draw a card for each creature you control with toughness 4 or greater.

Distribute three +1/+1 counters among any number of creatures you control.
Metamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Flying
Whenever Empyrean Griffin attacks, up to one target creature voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Permanents your opponents control can't phase in.

Trample, haste
When Sahra, the Consuming enters or attacks, sacrifice a permanent.
At the beginning of your end step, transform Sahra unless you've sacrificed two or more permanents this turn.

As Amber Hills enters, you may pay 2 life. If you don't, Amber Hills enters tapped.
{T}, Sacrifice Amber Hills: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

As long as Armed Vendor is enchanted or equipped, it gets +1/+0 and has menace.

{2}, Sacrifice Doctored Trail: Draw a card.
{T}, Sacrifice Doctored Trail: Destroy target Clue. If you do, draw a card.

Target player sacrifices a creature unless they discard a creature card.
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.)

Frozen Hinterlands enters tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Until end of turn, Shrouded Rooftops becomes a 3/3 white and black Illusion creature with with lifelink and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Choose a nonland permanent type, then destroy all nonland permanents that aren't of the chosen type.

Whenever a creature card is put into your graveyard from the battlefield, exile it. You lose life equal to that card's mana value. Put it onto the battlefield tapped at the beginning of your next upkeep.

Enchant creature
Enchanted creature gets +2/+2.
When enchanted creature dies, return it to the battlefield under its owner's control.