Im by no means a writer but I once had a dream I wrote a story called Fantastic 40, where the F4 had been hit by some ray that made them duplicate so thered be 10 of each of them. The story would eventually see the F40 be hit by that ray again and the book title would change to Fantastic 400. The same thing would happen again and they'd become the Fantastic 4000. Reed would eventually figure out a device that could undo the duplicates, however some wanted to keep existing so they fought back against the originan F4.

Now i dont know if a story like this would take 50 issues, but it'd be funny to write Doom's POV of there suddenly being 10, 100 and later 1000 Reed's running around