The Thermobular (Spectacular) is a small ring, which appears to be made of several lightning bolts connected end to end.

Any time the wearer is dealing lightning damage, the Thermobular (Spectacular) will amplify it, adding +1D10 additional lightning damage.

Once per day, the wearer can spend the charge to cast Lightning Bolt as a 3rd level spell (8D6), Dex save DC 15.

The charge resets with a long rest.