Arcanum, Finale Rune

As Arcanum, Finale Rune enters the battlefield,
choose Lightning or Fire.
Lightning—Enchantment spells you cast cost {2} less to cast.
Fire—Whenever an Enchantment enters or
leaves the battlefield, Arcanum deals 3 damage to
any target.
"The world bends to my will; all things are within my
grasp."
—Zach, Founded Theory