Reckless Fireweaver

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

Dispel

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

Whenever you cast a noncreature spell, Firebrand Archer deals 1 damage to each opponent.

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

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

{1}, {T}: Blisterspit Gremlin deals 1 damage to each opponent.
Whenever you cast a noncreature spell, untap Blisterspit Gremlin.

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

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

{U}, {T}: Draw a card, then discard a card.
Whenever you cast a noncreature spell, untap Zephyr Scribe.

Flying
Whenever you cast an artifact spell, you may untap target creature.

Swiftwater Cliffs enters tapped.
When Swiftwater Cliffs enters, you gain 1 life.
{T}: Add {U} or {R}.

{T}, Tap an untapped creature you control: Add one mana of any color.

When Alchemist's Vial enters, draw a card.
{1}, {T}, Sacrifice Alchemist's Vial: Target creature can't attack or block this turn.