In the Jim Starlin-revealed gatefold cover to Stormwatch #19, as reported here, he wrote;
Hellstrike, the Forecaster, Midnighter, the Engineer, Apollo, Jenny Soul, the Weird and Storm Control
Well, he was the titular character of a series by Jim Starlin and BErnie Wirightson created for DC in 1988.
He was made of energy, hailed from another dimension (suitable as a dimensional replacement for the Stormwatch team then) and was one of a race exploited an an energy source, something he rebelled against, and found his way to Earth in our dimension, where he possessed the body of a dead man. He recruited a bunch of DC superheroes to fight on behalf of his race, before blowing up. The end.
That is until he was revived in 2006 by Starlin in Mystery In Space, as his remaining energy knocked the equally disembodied Captain Comet somehow both giving them new bodies. And then fighting a church, or something.
And now Starlin has Stormwatch, it’s another change to bring him back, twenty-five years after his initial creation!