The shadowy figure in the video below is none other than an 18-year-old Dimebag (aka Diamond) Darrell, who can be seen working his way through a nearly seven-minute-long guitar solo with his trusty Dean ML.
In the clip, the young Dime makes noticeable references to several key six-string influences, especially Randy Rhoads and Eddie Van Halen, with a touch of Yngwie Malmsteen thrown in (and perhaps the showmanship and sartorial style of Jake E. Lee).
But beyond all that, Dime looks and sounds like a guitar prodigy through and through.
His playing is full of confidence—not to mention some nice, wide interval stretches and blazing speed. At this point—sometime in 1984 (we can't be sure exactly when it was filmed)—Pantera had only one or two independently released albums under their belt or in the works: 1983's Metal Magic and 1984's Projects in the Jungle.