msem-instigator

When Gleaming Waypoint enters, create a 1/1 red Scout creature token.
{T}: Add {U}, {R}, or {W}.

When Gleeful Deviser enters, create a 1/1 colorless Construct artifact creature token.

{3}, {T}: Glimmering Staff deals 1 damage to any target.
{5}, {T}: Put a -1/-1 counter on target creature.

When Glimpse in the Static enters, exile target creature an opponent controls until Glimpse in the Static leaves the battlefield.
At the beginning of your upkeep, target player creates a token that's a copy of the exiled card, then exiles that token.

Draw three cards. Discard your hand at the beginning of the next end step.

Prismatic — Whenever you cast a multicolored spell, draw a card.

Resolute — At the beginning of combat on your turn, if Glisterhorn's power is greater than its base power, tap target creature an opponent controls.

Tap another untapped artifact you control: Until end of turn, Glitched Carcass becomes an X/X Construct artifact creature, where X is the mana value of the tapped artifact. Activate only once each turn.

Vigilance
Whenever Glittering Narwhal is dealt damage, create a Treasure token. (It's an artifact with “{T}, Sacrifice this permanent: Add one mana of any color.”)

Gloam Gullet gets +1/+1 and has menace as long as you own a land card in exile or in your graveyard.

When Gloomy Waypoint enters, create a 1/1 black Scout creature token.
{T}: Add {W}, {B}, or {G}.

Whenever Glorybound Chorister attacks, put a +1/+1 counter on each other attacking creature you control.

When Glymna Blackrune enters, exile target player's graveyard.
During each of your turns, you may cast a creature card exiled with Glymna Blackrune.

When Gnuge-District Hoarder enters, each opponent loses 1 life. You gain life equal to the life lost this way.
Paranoia {1}{B} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Target player discards two cards. Then exile that player's graveyard.

Goblin Exploration Team gets +1/+0 for each non-Mountain land you control.

When Goblin Sniper dies, you may pay {R}. If you do, it deals 2 damage to target opponent or planeswalker.

Give any number of permanents and/or players with counters on them another counter of each kind already there. Whenever you cast a spell this turn, repeat that process.

Whenever you cast a spell you don't own, you may pay {1}{U}. If you do, put target nonland permanent on top of its owner's library.
{2}{B}: Exile the top card of target opponent's library face down. You may look at and cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell.

Put a +1/+1 counter on each creature you control. Repeat this process if you control a Soldier. Repeat this process again if you control a Knight.

When Golden Grizzly enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Goldtooth Slasher attacks, you may sacrifice an artifact or creature. If you do, Goldtooth Slasher gets +2/+0 and gains lifelink until end of turn.

Spells you cast with mana value 4 or greater cost {1} less to cast.

When Golna, the First Shah enters, create Shir, a legendary 3/3 white Cat creature token with trample.
Monument {5}{G}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)