msem-instigator

When Autumnal Resonants enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Create a 3/3 red and green Elemental creature token with haste.

Creatures can't attack you unless their controller pays {2} for each of those creatures.
Whenever a permanent is returned to a player's hand, create a 1/1 white and blue Bird creature token with flying.

Whenever this creature attacks, if you gained or lost life this turn, it gains flying until end of turn.
When this creature dies, create a 2/2 black Zombie creature token.

{T}: Target player exiles a card from their graveyard.
{2}, Sacrifice Remnant of Past Realities: Exile each opponent's graveyard. Draw a card.

Petal Blade deals 2 damage to target attacking or blocking creature. Create a Treasure token.

Mine Delver has first strike as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

You may exert Fleetfooted Survivalist as it attacks. (An exerted creature won't untap during your next untap step.)
Whenever an exerted creature you control deals combat damage to a player, draw a card.

This spell costs {2} less to cast if you control a creature with power 4 or greater.
Bonk deals 4 damage to any target.

Put a +1/+1 counter on target creature. It gains first strike until end of turn. You gain 2 life.

Monstrous Amalgam gets +X/+X, where X is the number of creature cards in your graveyard.
{B}, Reappropriate: Put a +1/+1 counter on Monstrous Amalgam. Activate only once each turn. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

At the beginning of each player's upkeep, that player loses 2 life unless they sacrifice a creature.
{4}{G}: Create a 2/2 green Wolf Elemental creature token.

Whenever a creature you control deals combat damage to a player, you may sacrifice it. If you do, draw cards equal to that creature's power.

Enchant nonland permanent
Enchanted permanent's activated abilities can't be activated and triggered abilities of enchanted permanent don't trigger.

Lone Hunter has indestructible as long as it has attacked alone this turn.
Whenever Lone Hunter becomes the target of a spell or ability you control, if it cost one or more mana to cast or activate, you may pay {1}. If you do, draw a card.

When Lust for Life enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Augmented — Whenever a creature you control enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may sacrifice Lust for Life. If you do, create a token that's a copy of that creature.

Grizzled Den enters tapped.
{T}: Add {R} or {G}.
{3}{R}{G}: Until end of turn, Grizzled Den becomes a Bear creature with trample in addition to its other types.
Scavenge {4}{R}{G}

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Put target creature [spell] on top of its owner's library.

Bloodprice {2}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)

{T}, Pay 1 life: Add {B} or {G}.
{2}, {T}, Sacrifice Walled Garden and another permanent: Draw a card. Activate only during your turn.

Whenever Ensnaring Possessor attacks, you may tap or untap target permanent.
{1}{U}, {T}: Until end of turn, target creature gets +1/+1 and gains “Whenever this creature attacks, you may tap or untap target permanent.” Activate only as a sorcery.

({T}: Add {G}.)
As Ancestral Glade enters, you may pay 1 life. If you don't, Ancestral Glade enters tapped.
Basic lands you control have “{T}: Add {G}.”

Look at the top two cards of your library. Put one of them into your hand, then you may have any number of players each mill three cards.

Target player discards two cards.
Cycling {2}{B} ({2}{B}, Discard this card: Draw a card.)
When you cycle Dementia's Clutch, target player discards a card.

Trample
Orodu, the Onyx Wave can't block.
Whenever Orodu attacks, defending player may sacrifice a creature. If they do, prevent all combat damage Orodu would deal this turn.

{T}: Add {C}.
{1}, {T}: Add {B}{G}.