msem-instigator

Put target creature card from a graveyard onto the battlefield under your control. If that card was put into that graveyard this turn, it enters with an additional +1/+1 counter on it.

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

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Cycling {B} ({B}, Discard this card: Draw a card.)

When Glowskate Channeler enters, create a green Aura enchantment token named Manta's Wings attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.”

When Glowspore Swarmgrounds enters, create two 1/1 blue Elemental creature tokens with flying.
Elementals you control get +1/+1.

When Gluttonous Empath enters, gain control of target nonland permanent for as long as you control Gluttonous Empath.

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

Prismatic — Whenever you cast a multicolored spell, you may discard a card. If you do, draw a card.

Whenever you cast an instant or sorcery spell, create a Treasure Clue token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color” and “{2}, Sacrifice this artifact: Draw a card.)

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.

Pressure {1}{B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Destroy target creature.

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.

Whenever you cast an instant or sorcery spell, target creature can't block this turn.

Each opponent sacrifices a creature. Whenever one or more players lose life this turn, repeat that process.

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.

Create a 1/1 white Citizen creature token. If you control a different permanent of each of three colors, create three of those tokens instead. Whenever a land you control enters 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.

When Godseeker Vanguard enters, create two 1/1 green Scout creature tokens.

At the beginning of your upkeep, you may discard a card. If you do, draw a card.
{T}: You may put a creature card from your hand onto the battlefield. If you do, put a +1/+1 counter on that creature.

When Godwatcher enters, search any player's library for a creature card, exile it, then they shuffle their library.
When Godwatcher dies, put the exiled card onto the battlefield under your control.

Concord — When Gold Pelt Responders enters, if there are four or more card types among permanents you control, you may exile target nonland permanent an opponent controls with mana value 4 or less until Gold Pelt Responders leaves the battlefield.

This spell costs {1} less to cast for each permanent you control that's a Dragon or a Hound.
Flying, haste
Whenever Gold Retriever attacks, abound. (You may cast a nonland card that costs less than this from your hand without paying its mana cost.)