msem-instigator

[+1]: Add {G}{U}{R}. Spend this mana only to cast creature spells.
[–2]: Reveal the top card of your library. If it's a creature card that costs less than the last spell you cast this turn, you may put it onto the battlefield. Otherwise, draw a card.
[–7]: Target creature becomes a legendary 20/20 green creature named Illusion of Kaur with hexproof and trample until end of turn.

When this creature enters, you may put a -1/-1 counter on a creature you control. If you do, look at the top five cards of your library. You may reveal a land card from among them and put it into your hand. Put the rest into your graveyard.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Ulek Crusher envisions a creature card, it gets +2/+2 until end of turn.

When Chikyu Champion enters, choose up to one for each land you control. Create a creature token for each of the chosen characteristics.
• 3/3 red Elemental Mouse with haste.
• 3/3 white and blue Fox with vigilance.
• 4/4 green Plant Dinosaur with trample.
• 4/4 red Dragon with flying.
• 4/4 blue Turtle with hexproof.
• 5/5 white Bear Beast.

When Undying Watcher enters, germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)
Sacrifice another creature: Undying Watcher gains indestructible until end of turn.

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Whenever Irreguleopard deals combat damage to a player, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Flash
Whenever Mischievous Capuchin or another Monk you control enters, tap target creature you don't control. If it was already tapped, it doesn't untap during its controller's next untap step.

Mill three cards. Pyromancer's Fury deals damage to any target equal to the number of instant and sorcery cards in your graveyard.

Ripplecore Trails enters tapped.
{T}: Add {R} or {G}.
{R}{G}, {T}, Sacrifice Ripplecore Trails: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Draw X cards and you gain X life, where X is the number of card types among permanents you control.

You may have Imitator of Success enter as a copy of any creature on the battlefield, except it has no mana cost and base power and toughness 1/1 if it's a token.
Successor {1}{U}{U} ({1}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost and base power and toughness 1/1. Succeed only as a sorcery.)

Glitch {1} (Remove one [restriction] for each time you pay the glitch cost.)
Create a token that's a copy of target [noncreature] permanent [you control].

{3}: Put a +1/+1 counter on Tinkerer's Assistant.

{1}, Sacrifice a creature: Put a +1/+1 counter on Chitterrax, then each opponent loses 1 life and you gain 1 life.

When Hideaway Agent enters, gain control of target nonland permanent with mana value 3 or less for as long as you control Hideaway Agent.

Until end of turn, target creature gets +2/+2 and gains trample and “Whenever this creature deals combat damage to a player, investigate.” (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Create a 2/1 red and white Fox creature token. If you're attacking, that token enters tapped and attacking.
Showcase {4}{R} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Lifelink
When Funerary Daoshi enters, return target creature card with mana value 3 or less from your graveyard to your hand.

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Pathway of Lost Sultans enters tapped.
When Pathway of Lost Sultans enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Flying
When Obsidian Hellkite dies, it deals 2 damage to up to one target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.
Foreshadow {4}{R}{R} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

{T}, Sacrifice Escape Hatch: Return target creature you control to its owner's hand.

Recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
Target creature you control fights target creature you don't control.

{T}: Add {G}.
{G}, {T}: Target creature gains trample until end of turn.

Bloodprice {U} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Counter target spell unless its controller pays {4}.