msem-instigator

{1}, Sacrifice Gasoline Canister: It deals 1 damage to any target. If a creature or planeswalker dealt damage this way would die this turn, exile it instead.

Whenever another creature you control enters, put a +1/+1 counter on each creature you control with lesser power or lesser toughness than that creature.

When Gate of Realms enters, you may search your library for a land card, reveal it, and put that card into your hand. If you do, shuffle.
{10}, {T}: Gate of Realms deals 3 damage to any target. This ability costs {1} less to activate for each different name among lands you control.

{T}, Pay 2 life: Add {B}.
{T}: Add one mana of any color. Spend this mana only to cast spells from your graveyard or activate abilities of cards in your graveyard.

When Gateway Statues enters, put a +1/+1 counter on target creature you control.
{T}: Add one mana of any color.

[+1]: Creatures you control get +0/+1 until your next upkeep. Untap those creatures.
[–2]: Put target tapped creature into its owner's library third from the top.
[–7]: You get an emblem with “Whenever a nonland permanent you control is put into a graveyard from the battlefield, each opponent sacrifices a nonland permanent.”

Flying
{1}, Sacrifice Gearcraft Observer: Look at target player's hand. Draw a card.

{1}{U}{R}, {T}: Create a token that's a copy of another target creature, except it's an artifact in addition to its other types and has “Whenever this creature is dealt damage, destroy it.”

When Gemplate Golem enters or dies, put a +1/+1 counter on target creature you control.

Motivate 3 (When this creature enters, you may motivate target creature with less power than this by putting three +1/+1 counters on it.)
When General Merthilios motivates a creature, that creature gains first strike, trample, and haste until end of turn.

If a source you control would deal exactly 1 damage to a permanent or player, it deals 3 damage instead.

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.

When Ghastly Ferry enters, create a 1/1 white Spirit creature token with flying.
Ghastly Ferry can't be blocked except by Spirits.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Creatures you control have deathtouch as long as they're attacking.
[+1]: Target creature you control must be blocked this turn if able.
[–2]: Create two 1/1 white Human creature tokens.
[–X]: Destroy target artifact or enchantment with mana value X and all other permanents with the same name as that permanent.

{T}: Draw a card, then discard a card.
Sacrifice Ghislain, Cryptbreaker: You may cast target creature, instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead. Activate only during your turn.

{2}, {T}: Prevent all combat damage that would be dealt to and dealt by target creature this turn.

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.

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}

At the beginning of combat on your turn, you may exert an untapped creature you control with power 4 or greater. If you do, attach Giant's Blade to that creature. (An exerted creature won't untap during your next untap step.)
Equipped creature attacks each combat if able.
Equipped creature gets +2/+0 and has haste.
Equip {3}

{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.

Equipped creature gets +2/+2 and has trample.
Equip {2}

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.

Flash
When Gilded Blade enters, you may attach it to target creature you control.
Equipped creature gets +1/+1.
Equip {1}

{T}: Target player mills a card.
{2}, Sacrifice Gilded Cipher: Draw a card.

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