Shadowman gets pulled into the future and all the superheroes in the Valiant universe are fighting each other or some shit--I never got a clear answer and I never read the rest of the crossover.
Oh, that. Unity, yeah? Well, the important thing about Unity, is that the second issues of those crossover bits had Walt Simonson covers, and as such, were completely rad. Okay, as for the story, what happened was that when Solar (another Valiant guy, natch, done real nicely by Barry Windsor-Smith) got his powers, he accidentally blew up the world. Eh, happens, right? This also caused crazy powers to go to his...assistant, I think? Anyhoo, she took the name "Mothergod" and set up shop in...I think it was called "The Lost Land"? Wherever Turok hung out and fought dinosaurs, and used the lost land's status of being outside of normal time (I know, but it made sense then) to pull a lot of the future in there with her. What was she gonna do? I forget, but it was likely to be some bad shit, I'll tell you whut.
The upshot of this crossover for Shadowman was that he met and briefly romanced a future-girl, who told him about his life and said he'd die a horrible death in, I think, May, 1997. So up until that time, he was functionally immortal. That part of his story I enjoyed thoroughly, but I lost interest immediately afterwards when stuff like the new costume and Aerosmith guest-appearance went down. Still, Shadowman was a pretty decent read at first. It was, however, no X-O Manowar, which was essentially Conan the Barbarian in a suit of alien space armor.
Early Valiant=Pretty decent. Midrange Valiant=Eh. Late Valiant/Acclaim had some bright spots but it didn't seem to last too terribly long. It had some high-concept appeal, including the original Shadowman dying right about when he was supposed to (I think, mind might be playing tricks on me) and the idea that the new and substantially different Acclaim/Valiant Universe was created when the X-O guy went back to his own time with his crazy space armor and changed history. Had potential, but didn't last real long.
Oh. Another neat Valiant character? Magnus, Robot Fighter. Not technically theirs, they just bought the license, but a guy in the future that goes around beating robots to death with his bare hands. The execution wasn't amazing, but you can't beat the concept.
--Scourge, who read wwwaaaayyyy too many comics back in the 90's, and probably still does.