msem-instigator

Sneaking Capuchin can't be blocked except by creatures with defender.
{U}: Counter target spell or ability that targets Sneaking Capuchin.

Up to two target creatures can't be blocked this turn. Until end of turn, whenever either of those creatures deals combat damage to a player or planeswalker, you draw a card.

Creatures with power less than Sneaking Peak's power can't block it.
At the beginning of your end step, if Sneaking Peak didn't attack this turn, put a +1/+1 counter on it.

Destroy target creature with flying. (Then exile this card. You may cast the creature later from exile.)

Target opponent discards two cards. You gain 2 life. (Then exile this card. You may cast the creature later from exile.)

Tap up to two target permanents. They don't untap during their controller's next untap step. You may put Snooze into its owner's library third from the top.

Snow Drift enters tapped. When it does, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this, then you may put that card into your graveyard.)
{T}: Add {U}.
{4}{U}: Snow Drift becomes an Elemental creature. (This effect lasts indefinitely.)

At the beginning of your end step, you may put a progress counter on Snowclearer.
[PROGRESS 1-2] Sacrifice Snowclearer: Add {C}.
[PROGRESS 3+] Sacrifice Snowclearer: Add two mana of any one color.

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.
Whenever you make first contact, scry 1. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

You may have Snowfield Doppelganger enter as a copy of any creature on the battlefield, except it has “While a player is choosing targets as part of casting a spell, that player must choose at least one other creature that shares a name with this creature if able.”

Prowess
When Snowline Ascetic enters, you may put target instant or sorcery card from your graveyard on top of your library.

Snowy Misthorn can block creatures with distorted as though it was tapped.

Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard. If that creature would die this turn, exile it instead.
Cycling {B} ({B}, Discard this card: Draw a card.)

As an additional cost to cast this spell, discard a card.
Draw two cards and crystallize twice. (Put a +1/+1 counter on a creature you control or create a Treasure. Then do it again.)

Reveal the top five cards of your library. You may put a permanent card revealed this way into your hand and the rest into your graveyard.

Flying
Whenever Soaring Biome attacks, create a Plains token, Island token, Swamp token, Mountain token, or Forest token. Sacrifice that land at the beginning of the next end step.
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.)

{T}: Add {C}.
{T}, Pay 1 life: Add {R} or {W}.

Create a 1/1 blue Bird creature token with flying.
Inscribe {2}{U} ({2}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

{T}: Add {C}. If Soaring Observatory entered this turn, add one mana of any color instead.
Tap three differently named untapped Academies you control: Add three mana in any combination of colors.

({T}: Add {G} or {U}.)
Soaring Rainforest enters tapped.
{1}, {T}: Add {G}{G} or {U}{U}.

Flying

Flying
When Soaring Skymage enters, mill four cards. You may return a creature card with flying from among the milled cards to your hand.

If you control seven or more creatures, you may cast Sociable Giant without paying its mana cost.
Trample

Bleed {0} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
Look at target player's hand.
Draw a card.

Look at the top four cards of your library. Put one of them into your hand, another on top of your library, and the rest into your graveyard.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)