It was here that Peter David also introduced a fascinating new facet to Madrox's powers. Now, every time he created a duplicate, he would have no idea what kind of personality the duplicate would have. That proved to be an issue right away when he was in danger and the duplicate that he created to save him decided to let him drop, instead!
Jamie slowly grew into his new leadership role with the team, learning to get past his early, carefree days. He began dating Siryn, for real this time.
During one mission for the X-Men, Jamie sent his duplicates into the future to investigate possible future scenarios. One of his dupes, though, was captured and branded with the same "M" tattoo that Bishop wore. That brand suddenly applied to all versions of Jamie. Siryn became pregnant and Jamie and Siryn seemed poised to move forward as a family but then tragedy struck.
As it turned out, the Jamie who first slept with Siryn (and got her pregnant) was actually a duplicate (Jamie was so drunk one night that he slept with M and Siryn and he didn't remember which one he slept with as the "real" Jamie) and so as soon as Jamie touched the baby, he re-absorbed it into himself. As you might imagine, that was highly traumatizing to both Siryn and Jamie.
Jamie ended up leaving the team and ending up in the future, where he fell in love with Layla Miller, who he had first known as a young girl, but she had been trapped in the future on Jamie's visit to the future and grown into adulthood. She and Jamie returned to the present and they actually got married. After a long, decade=-long run, X-Factor came to an end and Jamie and Layla retired together. That was supposed to be their happy ending.
Tragically, however, it turned out that the Terrigen Mists, which Black Bolt had exploded into Earth's atmosphere in an attempt to keep them from THanos, were fatal to mutants. Jamie was one of the first mutants to discover this when he was then killed by the Terrigen Mists in the event series, Death of X. However, this being Jamie Madrox, it is probably only a matter of time before we learn that it was a duplicate who died instead. Especially with a possible new movie coming out starring him!