msem-instigator

This spell costs {1} less to cast for each card put into your graveyard from anywhere this turn.
Target creature gets -4/-4 until end of turn.

Vigilance, trample
Each creature you control can't have power less than its toughness. (If it would have less, it has as much as its toughness instead.)
Each creature your opponents control can't have toughness greater than its power.

{1}{B}, Discard a card: Exile target creature card from your graveyard. Create a token that's a copy of that card, except it's a 5/5 black Horror.

When Grave Wrangler enters, you may return target creature card from your graveyard to your hand.

When Greedy Rapscallions enters, mill three cards. If two or more nonland cards were put into your graveyard this way, put a +1/+1 counter on Greedy Rapscallions.

Whenever Greenscale Bully deals combat damage to a player, create a Treasure token. (It's an artifact with “{T}, Sacrifice this permanent: Add one mana of any color.”)

When Grievous Buccaneer enters, it voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Grievous Buccaneer phases in, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Flying, lifelink

{2}, {T}: Create a Treasure token. (It's an artifact with “{T}, Sacrifice this permanent: Add one mana of any color.”)
{W}{U}{B}{R}{G}, {T}, Sacrifice Grim's Warchest: Exile target creature.

Flash
Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
When Grim enters, if you sacrificed a permanent this turn, exile target tapped creature.

Whenever Grin, Scourge of Goresand attacks, when you next cast an instant or sorcery spell with mana value 3 or less this turn, copy that spell. You may choose new targets for the copy.
Dash {2}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

When Grisly Reaper enters, you may exile a creature card from your graveyard. When you do, create a 1/1 black Skeleton creature token.

You may play Grisly Ruins from your graveyard as long as seven or more cards are in your graveyard.
Grisly Ruins enters tapped.
{T}: Add {B} or {G}.
Cycling {1}{B}{G} ({1}{B}{G}, Discard this card: Draw a card.)

Resolute — {T}: Grizzled Cutthroat deals 1 damage to any target. Activate only if Grizzled Cutthroat's power is greater than its base power.

Flash
When Guppyfin Duelist enters, create a green Aura enchantment token named Piranha's Prowess attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.” Untap that creature.

Whenever H.S.S. Demeter becomes blocked by a creature, gain control of that creature.
Whenever H.S.S. Demeter deals combat damage to a player, draw two cards.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Once during each of your turns, you may cast a copy of a card in your graveyard by exiling that card in addition to its other costs.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Happy Manta deals combat damage to a player, draw a card for each card type among spells you've cast this turn.

{U}, Give yourself a lore counter: Scry 1. This ability costs {2} more to activate for each lore counter you have.
{6}{U}, Remove three lore counters from yourself, Sacrifice Harbinger of Giradrus: Draw seven cards, then create two 4/4 red Dragon creature tokens with flying.

Enchant creature
Enchanted creature gets +2/+2.
Concord — As long as there are four or more card types among permanents you control, enchanted creature has slipstream. (This creature can't be blocked as long as only creatures with slipstream are attacking.)

When Harried Submersible enters, target opponent creates a 1/1 blue Tentacle creature token.
Whenever Harried Submersible deals combat damage to a player or planeswalker, draw a card.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

First mate—Your starting deck contains at least twelve Vehicles. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Haste
{R}{W}, {T}: You may put a Vehicle card from your hand onto the battlefield. That Vehicle gains haste and becomes an artifact creature until end of turn.

Augmented — Whenever you cast a spell from your hand, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, exile cards from the top of your library until you reveal a nonland card with mana value less than that spell's mana value. You may cast that card without paying its mana cost. Put the revealed cards not cast this way on the bottom of your library in a random order.

Whenever you cast a spell with two or more black mana symbols in its mana cost, you draw a card and you lose 1 life.

When Helicos Aberration enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)