msem-instigator

When Frost Walker becomes the target of a spell or ability, sacrifice it.

Deathtouch
{B}{G}, Exile Frosted Adder from your graveyard: Return another target creature card from your graveyard to your hand.

When Frostfield Swordsman enters, arm it. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Enchant creature
Enchanted creature gets +2/+2 and attacks each combat if able.

{1}{W}: Exile Furtive Witch. If you do, exile another target nonland permanent. Return both of those cards to the battlefield at the beginning of the next end step under their owners' control.

Flying
If a triggered ability of another permanent you control would trigger for the first time each turn, that ability triggers an additional time.

Whenever Gallant Chevalier attacks or blocks, put a +1/+1 counter on it and each other creature you control with a +1/+1 counter on it.

When Ghastly Ferry enters, create a 1/1 white Spirit creature token with flying.
Ghastly Ferry can't be blocked except by Spirits.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

When Ghoulsaber enters, create a 1/1 white Spirit creature token with flying, then attach Ghoulsaber to it.
Equipped creature gets +2/+2.
Equip {2}

When Gilded Yak enters, you gain 3 life.

Defender
When Glacial Buttress dies, tap each creature that dealt damage to it this turn. Those creatures don't untap during their controller's next untap step.

{G}{U}: Glacier Tortoise gets +5/-5 until end of turn. Activate only once each turn.

Enchant creature
Enchanted creature has “You can't lose the game and your opponents can't win the game.”

Harvest (You may tap any number of creatures you control as you cast this spell. If you do, reduce this spell's mana cost by their total power.)
Target creature you control deals damage equal to its power to target creature you don't control.

Rapport — Whenever Grayce Blaen and at least one other creature you control become tapped, scry 1, then reveal the top card of your library. If it's a land card, you may put it onto the battlefield tapped.

{7}{G}: Monstrosity 6. (If this creature isn't monstrous, put six +1/+1 counters on it and it becomes monstrous.)

Greenheart Den enters tapped.
{T}: Add {G}.
{G}, {T}: Target creature you control gets +1/+1 until end of turn. Activate only as a sorcery and only if you control a green creature.

When Greenheart Squirrel enters, look at the top four cards of your library. You may reveal a basic land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Rapport — Whenever Grinning Fox and at least one other creature you control become tapped, tap another target creature. That creature doesn't untap during its controller's next untap step.

{4}{G}{G}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
When Grizzly Matriarch becomes monstrous, destroy target noncreature permanent an opponent controls.

Enchant player
Creature tokens enchanted player controls get +1/+1.

You may activate loyalty abilities of target planeswalker you control an additional time this turn.
Fabled {1}{U}{U} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that planeswalker.)

{T}: Add {C}.
{T}, Pay 1 life: Add {B} or {G}.

When Haunted Hermit enters, choose one —
• Put a +1/+1 counter on Haunted Hermit.
• Create a 1/1 white Spirit creature token with flying.

Flying
When Heartless Host enters, arm target creature. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)