msem-instigator

When Red-Crowned Admiral enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Each creature you control with a +1/+1 counter on it has flying.

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

{4}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Draw four cards.
Metamorph {3}{U}{U} (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.)

Reach, trample
When Anran, Root Steward enters, destroy up to three target noncreature permanents. For each permanent destroyed this way, its controller creates a colorless enchantment land token named Paradise with hexproof and “{T}: Add one mana of any color.”

I — Reveal the top four cards of your library. Put a creature card with mana value 4 or less from among them onto the battlefield and the rest into your graveyard.
II — Any number of target creatures you control fight target creature you don't control.
III — Put up to three target cards from your graveyard on top of your library in any order.

Once each turn, when Vedu, the Deepdrinker enters or you attack with one or more Horrors, you may tap up to two target permanents. If Vedu isn't a token, put two stun counters on each of those permanents.
{2}{U}{U}, Discard Vedu: Create a token that's a copy of Vedu, the Deepdrinker, except it's 4/4 and isn't legendary. Activate only as a sorcery.

Flying
Stormcloud Drake gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever Stormcloud Drake attacks, tap target creature defending player controls.

Trample

Look at the top three cards of target player's library. Put one back and exile the rest.
Coalesce {5}{U} (You may cast this from your graveyard for {5}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Whenever Lurk at Vision's Edge attacks, defending player exiles the top five cards of their library.

Flying
Aedryd, Spectral Liege's power and toughness are each equal to the number of creatures you control.
{2}{W/U}: Another target creature you control gains flying until end of turn. When that creature leaves the battlefield this turn, create a 1/1 white Spirit creature token with flying.

When Rotting Greatwurm dies, put three +1/+1 counters on target creature you control.
Fleeting {2}{G} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

If you would draw a card, you may return an instant or sorcery card from your graveyard to your hand instead.
{U}: Draw three cards.

Magnificent Palace enters tapped.
As Magnificent Palace enters, choose two colors.
{T}: Add one mana of any of the chosen colors.

Flying, haste
Whenever Cyrukan's Elite attacks, create
a 4/4 white Angel Soldier creature token with flying. If it's the first time Cyrukan's Elite has attacked this turn, untap all creatures you control. After this phase, there is an additional combat phase.

Vigilance
Whenever Liege of Asham attacks or blocks, other attacking or blocking creatures you control get +1/+1 until end of turn.

Audition for white. If you create a Role this way, untap the creature it enchants. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)

As Imperial Barracks enters, you may reveal a Mountain or Plains card from your hand. If you don't, Imperial Barracks enters tapped.
{T}: Add {R} or {W}.

Enchant permanent
Enchanted permanent is a land with “{T}: Add {G}{W}{U}” and loses all other card types and abilities.
{1}, Discard Song of Shoals: Add one mana of any color. Scry 1.

When Backwoods Cultivator enters, put a +1/+1 counter on target creature you control.
When Backwoods Cultivator dies, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)

You may pay {1}{R}{R} and tap an untapped Knight you control rather than pay this spell's mana cost.
Target untapped creature you don't control blocks this turn if able. Other creatures can't block this turn.

Nonbasic lands target player controls don't untap during that player's next untap step.
Fabled {3}{R} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

{T}: Add {C}.
{1}: Hoof Cliff Horngrove becomes a 2/2 Elemental creature until end of turn. It's still a land.
Menagerie — Whenever Hoof Cliff Horngrove becomes a creature, it gains your choice of +1/+1, flying, first strike, lifelink, trample, or haste until end of turn. This ability triggers only if there are five or more creature types among creatures you control.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Target creature you control gets +1/+0 until end of turn if you're in a renaissance. Then that creature deals damage equal to its power to target creature you don't control.

Whenever you cast a cryptic spell, put a +1/+1 counter on Spiny Lizard. (Artifacts, enchantments, and modal spells are cryptic.)
When Spiny Lizard dies, you gain life equal to its power.