Shifting Grift

Spree (Choose one or more additional costs.)
+ {2} — Exchange control of two target creatures.
+ {1} — Exchange control of two target artifacts.
+ {1} — Exchange control of two target enchantments.

Wash Out

Return all permanents of the color of your choice to their owners' hands.

Bogstomper

Vampiric Link

Enchant creature
Whenever enchanted creature deals damage, you gain that much life.

Stop That

Target player discards a card.
Gotcha — If an opponent audibly flicks the cards in their hand, you may say "Gotcha!" When you do, return this card from your graveyard to your hand.

Mantle of Tides

Equipped creature gets +1/+2.
Whenever you draw your second card each turn, attach this Equipment to target creature you control.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Ice Over

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.

The Master, Mesmerist

{T}: Target creature an opponent controls with power less than or equal to The Master's power gains skulk until end of turn. Goad it. (A creature with skulk can't be blocked by creatures with greater power.)
Whenever a creature with skulk deals combat damage to one of your opponents, put a +1/+1 counter on The Master and draw a card.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Snow-Covered Swamp

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Snow-Covered Island

Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Helm of the Ghastlord

Enchant creature
As long as enchanted creature is blue, it gets +1/+1 and has "Whenever this creature deals damage to an opponent, draw a card."
As long as enchanted creature is black, it gets +1/+1 and has "Whenever this creature deals damage to an opponent, that player discards a card."

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)

Time Ebb

Put target creature on top of its owner's library.

Trespassing Souleater

{U/P}: This creature can't be blocked this turn. ({U/P} can be paid with either {U} or 2 life.)

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Sickle Ripper

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Nausea

All creatures get -1/-1 until end of turn.

Shell Skulkin

{3}: Target blue creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Black Dragon

Flying
Acid Breath — When this creature enters, target creature an opponent controls gets -3/-3 until end of turn.