20 dmg more efficient... but still not too great

Kicker (You may pay an additional as you cast this spell.) This spell can't be countered. Urza's Rage deals 3 damage to any target. If this spell was kicked, instead it deals 10 damage to that permanent or player and the damage can't be prevented.

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.