msem-instigator

{T}: Add {C}. Exile a card from your graveyard.
{3}: Until end of turn, Forgotten Temple becomes an X/X creature, where X is the number of cards exiled by it. It's still a land.
As long as a creature card with flying is exiled by Forgotten Temple, it has flying. The same is true for first strike, double strike, deathtouch, experience, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Trample, haste
When Red Pelt Hart deals combat damage to a player, return it to its owner's hand.
At the beginning of your end step, sacrifice Red Pelt Hart.

At the beginning of your upkeep, gain control of up to one target noncreature, nonland permanent for as long as you control Flawless Heist. Then if you control five or more permanents you don't own, you win the game.

Lifelink
Whenever Morning's Warden becomes the target of a spell or ability an opponent controls, exile target creature that player controls.

Vigilance
Cat creatures you control have vigilance.
When Savannah Scout enters, create a 2/2 white Cat creature token.

Destroy target creature or planeswalker. Create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

Stampede — Whenever Exuberant Hunter and a creature with greater power attack, draw a card.

Reconstruct {4}{B}{B}{B} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)
Destroy all creatures. If The Afterlife Takes Its Due was reconstructed, create an X/X black Zombie Horror creature token, where X is the number of creature cards that have been put into graveyards this turn.

When Awoken Animus enters, create two 1/1 colorless Shapeshifter creature tokens with changeling. (They're every creature type.)
{2}, Discard Awoken Animus: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Each player discards their hand and sacrifices all permanents they control, draws seven cards, then abounds seven times. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

Untap target artifact or creature. It gains hexproof and indestructible until end of turn.

{1}, {T}, Move a -1/-1 counter from another creature onto Dockside Healer: You gain 2 life.

Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Vithian Arcanist gets +2/+0 and has haste as long as you've cast an instant or sorcery spell this turn.
When Vithian Arcanist enters, add {U}{B}{R}. Spend this mana only to cast instant and/or sorcery spells.

Griffin Country enters with a feather counter on it.
Creatures with flying you control get +1/+1.
{U}, Remove a feather counter from Griffin Country: Put a flying counter on target creature you control.
{2}{U}, Remove a feather counter from Griffin Country: Search your library for a creature card with flying, reveal it, put it into your hand, then shuffle.

Create X 4/4 white Angel creature tokens with flying.
Flashback {X}{W}{W}{W}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Return up to two target creature cards from your graveyard to your hand.

Defender
Whenever you cast an instant or sorcery spell, you may untap Almgrove Sentinel.
{T}: Almgrove Sentinel deals 1 damage to any target.

Vigilance
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Champion of Destinies becomes renowned, you become the monarch.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Tap target creature you don't control.
[Lore III] Tap target creature you don't control. It doesn't untap during its controller's next untap step.

WZ-18 Troublemaker enters with a +1/+1 counter on it.
When WZ-18 Troublemaker dies, put its counters on target creature you control.
{1}{R}, Exile WZ-18 Troublemaker from your graveyard: It deals 2 damage to each opponent.

{T}: Add one mana of any color. If you control another nonbasic land, Abandoned Monument doesn't untap at the beginning of your next untap step.

Deathtouch
Whenever a creature dealt damage by Barbed Beast this turn dies, transform Barbed Beast.

Flying
{T}, Tap another untapped creature in Heaven's Gale Harrier's pack: Tap target creature. (Two or more creatures you control with equal power are in a pack.)