Sand Demon

Eddie's first appearance was the result of a fiasco. His wrestler King Crusher was mutated to a hulk-like giant. Slick was fleeing for his life before Firestorm intervened. Firestorm saved Slick's life but also exposed the entire steroids-providing ring to the authorities. 
 
The mob blamed the entire affair on Slick. His criminal career ended and a bit later Eddie Slick was buried alive in the Nevada desert. Instead of dying, Eddie mutated to a being composed of and able to control sand. He tracked his killers to Las Vegas and went on a rampage while trying to return the favor. Firestorm was at the time looking for Martin Stein, his missing component. He tried to make "Martin" come to his senses. Once the hero realized this was not Martin at all and Slick was effectively insane, Firestorm felt he had no reason to hold back. He solidified Eddie's sand form to glass and left it broken on the pavement.