msem-instigator

When Goldengrain Alseid enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.

Reach, trample
Improve {1}{B/G} ({1}{B/G}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever one or more +1/+1 counters are put on Gorganith, Ruin Maw, you may search your library and/or graveyard for a creature card with mana value equal to or less than the number of +1/+1 counters on Gorganith and put it onto the battlefield. If you search your library this way, shuffle.

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Enchant land
When Grace of Timber enters, put a +1/+1 counter on target creature you control.
Enchanted land has “{T}: Add two mana of different colors.”

Flying

Flash
If a +1/+1 counter would be put on another creature, that counter is put on Grafted Physician instead.

Whenever a creature you control enters for the first time each turn, create a 1/1 Scout creature token that's all colors.

{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.

As an additional cost to cast this spell, exile two cards from your graveyard with the same mana value.
Search your library for a card with the same mana value as the exiled cards, reveal it, put it into your hand, then shuffle.

When Graygulch Turncoat enters, you may post a bounty on target creature. If you do, each opponent loses life equal to the number of bounty counters on creatures. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

If it isn't an extra turn, take an extra turn after this one. (Cast a copy of this spell once while this creature is on the battlefield.)

Flying, trample
When Greedstoker Demon enters, you lose X life and create X Treasure tokens, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
You can't sacrifice more than one Treasure each turn.

Whenever another Hound you control enters, put a +1/+1 counter on Greypelt Initiate.

Whenever a creature dies, put a +1/+1 counter on Grim Armory.
Whenever a creature you control enters, you may move a +1/+1 counter from Grim Armory onto it.

As Grim Bastion enters, you may pay 2 life. If you don't, Grim Bastion enters tapped.
{T}, Sacrifice Grim Bastion: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

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.)

Target creature gets +2/+2 until end of turn.
Landfall — If you had a land you control enter this turn, that creature gets +4/+4 until end of turn instead.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {B} or {G}.

Once each turn, when Groz, the Nightshaper enters or you attack with one or more Horrors, you may return target nonlegendary creature card from your graveyard to your hand. Then if Groz isn't a token, create a token that's a copy of that creature card.
{2}{B}{B}, Discard Groz: Create a token that's a copy of Groz, the Nightshaper, except it's 4/4 and isn't legendary. Activate only as a sorcery.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {R} or {G}.

Flying
Each spell costs {2} more to cast except during its controller's turn.

First strike
Whenever Guardian of the Eclipse attacks, you may exile another target attacking creature you control, then return it to the battlefield under your control tapped and attacking.

Target permanent gains hexproof and indestructible until end of turn. Scry 1.

Guidestone enters tapped.
{T}: Add {C}.
{2}, Sacrifice Guidestone: Draw a card.

As Guiding Light enters, choose a color.
You have hexproof from the chosen color.
If a creature you control would be dealt damage by a source of the chosen color, prevent 1 of that damage.