Memnite

Counterspell

Retraction Helix

Until end of turn, target creature gains "{T}: Return target nonland permanent to its owner's hand."

Tolaria West

Tolaria West enters tapped.
{T}: Add {U}.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with mana value 0, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Battered Golem

Battered Golem doesn't untap during your untap step.
Whenever an artifact enters, you may untap Battered Golem.

Island

Nettle Drone

Devoid (This card has no color.)
{T}: Nettle Drone deals 1 damage to each opponent.
Whenever you cast a colorless spell, untap Nettle Drone.

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.")

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Mountain

Herbal Poultice

{3}, Sacrifice Herbal Poultice: Regenerate target creature.

Reckless Fireweaver

Whenever an artifact you control enters, Reckless Fireweaver deals 1 damage to each opponent.

Serum Visions

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Molten Nursery

Devoid (This card has no color.)
Whenever you cast a colorless spell, Molten Nursery deals 1 damage to any target.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Banishing Knack

Ornithopter

Glaring Fleshraker

Whenever you cast a colorless spell, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."
Whenever another colorless creature you control enters, Glaring Fleshraker deals 1 damage to each opponent.