Thundering Spell

Spend 2 sorcery points. Your electrical spells deal Thunder damage.

Benefit: On any spell that deals electrical damage, you also deal 1d4 points of Thunder damage per caster level. This effect occurs on the same round that the spell first causes electrical damage, and has no additional effect even if the spell has a non-instantaneous duration. If a spell allows the target to make a saving throw for half or no damage and the target makes their save, the sonic damage is also halved or negated. The spell gains the "sonic" descriptor.