msem-instigator

Motivate 1 (When this creature enters the battlefield, you may motivate target creature with less power than this by putting a +1/+1 counter on it.)

First strike

({T}: Add {U} or {R}.)
Frostfire Geysers enters the battlefield tapped unless you control a basic Island or a basic Mountain.

({T}: Add {B} or {G}.)
Fungal Mire enters the battlefield tapped unless you control a basic Swamp or a basic Forest.

Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gets +1/+0 and gains haste.

Vigilance, reach
Identity — As long as you control at least two other creatures that share a creature type with Gallord of the Order, other creatures you control get +1/+1 and have first strike.

Search your library for a creature or planeswalker card, reveal it, put it into your hand, then shuffle.

Create a 1/1 white Soldier creature token. It gets +1/+1 and gains first strike until end of turn.

As an additional cost to cast this spell, discard a card.
Draw three cards.

Whenever a creature attacks, if its toughness is greater than its power, untap it.

Populate, then you gain 2 life. (Create a token that's a copy of a creature token you control.)

When Gendran Hostess enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Motivate 3 (When this creature enters the battlefield, 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.

Enchant creature
Enchanted creature and other creatures you control that share a creature type with it get +1/+1 and have vigilance.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Regenerate target creature. (The next time that creature would be destroyed this turn, it isn't. Instead tap it.)

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.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Glimmerwing Trickster deals combat damage to a player, scry 2.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Glintfeather Sage or another creature with flying you control dies, you may pay {1}. If you do, draw a card.

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.

({T}: Add {R} or {G}.)
Glittering Grove enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

({T}: Add {W} or {B}.)
Gloomcover Steppe enters the battlefield tapped unless you control a basic Plains or a basic Swamp.

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 the battlefield with an additional +1/+1 counter on it.

When Goblin Arsonist dies, you may have it deal 1 damage to any target.