Adrovelissinndan's (Adro's) Bolt of Fire and Lightning

As you hold both of the required scales in your hands, a spark ignites in the palm of the hand with the Red (or Gold or Brass) dragon scale quickly manifesting into a sphere of flaming gas while crackling energy manifests in the hand holding the Blue (or Bronze) dragon scale before you quickly slam the scales together coalescing the two spheres into a bolt of the combined energy that shoots off at one target you can see within 120 ft, make a ranged spell attack, on a hit the spell deals 5d10 fire damage and 5d10 lighting damage, you have advantage if the target is wearing metal armour or is standing in SALT water. If you miss, the target and EACH creature (even friendly ones [the evocation wizards "Sculpt Spells" ability does NOT and can NOT effect the explosion if you miss]) in 10ft of the target must make a dexterity saving throw taking 2d10 fire damage and 2d10 lightning damage on a success, or half as much on a fail.