Titanic Bolt

Kicker {w}{r}{r/w}{r/w} (You may pay an additional {w}{r}{r/w}{r/w} as you cast this spell.)
Titanic does 4 damage to target creature, and you gain 4 life.
If Titanic Bolt's kicker cost was paid, it deals 7 damage to target creature, and you gain 7 life instead.