Certain characters missed being part of events, status quos, teams, etc. because they were dead or otherwise written out at the time. The obvious example is Jean, who wasn't around for storylines like Decimation or Utopia. Which characters do you wish had been part of an era that they weren't and how do you think they would have changed things?
For one, I would have loved to have seen a non-de-aged Magik as part of the original X-Force when the New Mutants broke away from the mansion with Cable. She would have added an edge to the team and I can imagine her butting up against Cable's militaristic leadership.