msem-instigator

Up to two target creatures each get +X/+X until end of turn. They must be blocked this turn if able.

When Genome Mapper enters, create a Function token with “Create an X/X green Mutant creature token, where X is this spell's mana value.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Discard up to two cards, then draw that many cards.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

When Gharsha, Monstrous Quarry enters, each opponent creates a 1/1 green Elf creature token.
Whenever a creature you control becomes blocked, you may pay {1}. If you do, put a +1/+1 counter on that creature.

Ghastly Castle enters tapped unless another player controls a land that could produce {U} or {B}.
{T}: Add {U} or {B}.

Creatures can't attack you or a planeswalker you control unless their controller pays {2} for each of those creatures.
Creatures can't block Ghastly Scraper unless their controller pays {2} for each of those creatures.

Flying
When Ghastly Spirit enters, mill four cards, then return a nonland card from your graveyard to your hand.

Destroy target creature or planeswalker. If a planeswalker is destroyed this way, search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles.

Ghost Sloop can't be blocked.
Crew 4 (Tap any number of creatures you control with total power 4 or greater: This Vehicle becomes an artifact creature until end of turn.)
Exile a creature card from your graveyard: Ghost Sloop becomes an artifact creature until end of turn.

Flying
Creatures your opponents control get -1/-0.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Ghostly Hounds mentors a creature, that creature can't be blocked this turn.

When Ghoulsaber enters, create a 1/1 white Spirit creature token with flying, then attach Ghoulsaber to it.
Equipped creature gets +2/+2.
Equip {2}

{2}, Sacrifice Giant's Remains: Draw a card.
{5}, Exile Giant's Remains from your graveyard: Create a tapped 4/4 black Skeleton Giant artifact creature token.

Creatures you control get +1/+1 and gain trample and lifelink until end of turn.

Sacrifice a creature. At the beginning of the next end step, return that card from a graveyard to the battlefield under your control with two +1/+1 counters on it, except it's a black Demon instead of its other colors and types.

Gifted Arcanomancer gets +1/+1 as long as you control a Mountain.
{3}{R}: Exile the top card of your library. Until end of turn, you may play that card.

Enchant creature
Enchanted creature gets +2/+2.
Whenever an enchanted creature you control deals combat damage to a player, you may put a permanent card from your graveyard on top of your library.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Put a +1/+1 counter on up to one other target creature you control.
[Lore III] Target creature must be blocked this turn if able.

When Giku Weaponsmith enters, create two colorless Equipment artifact tokens with “Equipped creature gets +1/+1” and equip {1}.

Gild-Cloak Strider can't be blocked by creatures with greater power.
{1}{W/U}: Return Gild-Cloak Strider to its owner's hand.

When Gilded Authority enters, create two Treasure tokens. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Creatures your opponents control get -1/-0.

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
When Gilded Champion becomes renowned, you may search your library for an Equipment or Aura card, reveal it, put it into your hand, then shuffle.

As you harmonize, you may choose another harmony ability to trigger. (They can't be the same harmony.)
Harmony — Scry 1.

Flying
When Gilded Guardian dies, you may search your library for a legendary card, reveal it, put it into your hand, then shuffle.