msem-instigator

When Gau Ding Soulhoard dies, create X 1/1 colorless Spirit creature tokens, where X is its power.
Scavenge {4}{B} ({4}{B}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Enchant opponent
Enchanted player plays with the top card of their library revealed.
Whenever enchanted player casts a spell, you may have them mill a card.

When Gemcrusher Turtle enters, choose one —
• Destroy target artifact.
• Gemcrusher Turtle fights up to one target creature.

Flying
When Gemscale Drake enters, create a Treasure token.
Whenever Gemscale Drake deals combat damage to a player, scry 1. If you control three or more artifacts, draw a card instead.

Whenever you cast a spell with mana value 5 or greater, create an X/1 red Mutant creature token with trample and haste, where X is that spell's mana value. Exile that token at the beginning of the next end step.

Once during each of your turns, when you sacrifice a permanent, you may have target opponent lose 3 life unless they sacrifice a nonland permanent or discard a card.

{T}: Add {C}.
{T}: Choose a color from among permanents you control. Add one mana of that color.

Enchant creature
Enchanted creature and other creatures you control that share a creature type with it get +1/+1 and have vigilance.

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.

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.