ay man i was wandering if someone can help me, I only read a few comics back in the whole onslaught series, never collected them but now im readin a series thats pretty much right after onslaught and there talking about all these mutant that died while fighting onslaught but who all died while fighting him?
Pretty much, it was believed that all the non-mutant superheroes (Thor, Hulk, Fantastic Four, etc) died fighting Onslaught. This happened because Onlsaught became pure psionic-energy and mutant abilities would only fuel his power. The powers & life force of the Avengers, Fantastic Four & the Hulk are used to destroy Onslaught. Before their full deaths, however, Franklin Richards (son of Mr. Fantastic & Invisible Woman), who was captured by Onslaught, creates an full pocket dimension where the superheroes are reborn and "rediscover" their powers. They are transferred back into the real world by a Celestial, who sacrifices her conciousness in order to merge Franklin's dimension with the real one.
Also, in Bishop's future, it was Onslaught who exterminated the X-Men and, roundabout wise, Xavier was the X-traitor Bishop heard of. However, Bishop, being in the current timeline at this event, absorbed the energy blast Onslaught used that would have killed off the X-Men.