Bararaq, (雷光, Bararāku, Lightning) is a technique used by the Metal Vessel of Sinbad. It gets its power from Sinbad's Djinn, Baal. Sinbad can call forth a lightning bolt and direct it at the intended target. It's powerful enough to create a massive explosion but when he first used it on a Raging Unicorn after he obtained Baal, it simply fried the creature although it died in one strike.
Trivia
The name of this magic is probably derived from the Arabic word براق barrāq "flashing" (itself derived from the related Arabic word برق barq "lightning").