Retraction Helix

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

Phyrexian Walker

Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Banishing Knack

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

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.

Dispel

Reckless Fireweaver

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

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Battered Golem

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

Seat of the Synod

Steelfin Whale

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Whenever an artifact you control enters, untap Steelfin Whale.

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.