Bolt of the Dragon lord

The height of draconic spellcasting. You raise your hand into the air and summon a bolt of red draconic lightning and catch it. You can then throw the bolt up to 150 feet. The bolt creates a shockwave when it touches a surface. Each creature within a 40 foot sphear must make a dexterity saving throw or take 12d6 lightning damage or half as much on a success. The bolt lingers for until the caster detonates it with an action, creating a second shockwave. Each creature within a 40 foot sphear must make a dexterity saving throw or take 12d6 lightning damage or half as much on a success.