Atomic Fireball

The caster of this spell focuses upon the inherent and unstable energies within a rod and sphere of the mysterious metal “necrotite”, transmuting the very matter into pure energy.  As the metal is launched, anywhere within the caster’s sight, it creates a massive explosion a mile across; dealing 20d6 Force, 20d6 Fire, and 40 necrotic damage, and half as much fire and force damage on a successful dexterity saving throw.