Rainclouds don't last long in Shiv, but that doesn't stop the lightning.

Arc Lightning

Arc Lightning deals 3 damage divided as you choose among one, two, or three targets.

The List

Khans of Tarkir

Magic Online Promos

Ugin's Fate

Arc Lightning deals 3 damage divided as you choose among one, two, or three target creatures and/or players.

"It is vain to look for a defense against lightning."
—Publius Syrus, Maxim 835, trans. Lyman

If some of the creatures are illegal targets as Arc Lightning tries to resolve, the original division of damage still applies but no damage is dealt to the illegal targets. If all targets are illegal, Arc Lightning doesn’t resolve.

You choose how many targets Arc Lightning has and how the damage is divided as you cast the spell. Each target must receive at least 1 damage.