This article contains spoilers for Fantastic Four #25, by Dan Slott, R.B. Silva, and Jesus Aburtov.
The Fantastic Four have just lost their most powerful member. The son of Mr. Fantastic and the Invisible Woman, Franklin Richards is considered an Omega level mutant - a mutant whose dominant power is deemed to register, or to reach, an undefinable upper limit. Galactus himself considers Franklin the most powerful mutant ever born, and that shouldn't really come as much of a surprise. At his peak, Franklin possesses the ability to manipulate the nature of reality itself. He can create entire universes at will - and, indeed, in the wake of 2015's Secret Wars, he was actually personally responsible for rebuilding the entire Multiverse.
There's just one problem; Franklin Richards has been losing his powers. That news has sent shockwaves through the mutant community, with Charles Xavier fearing it suggests even an Omega's abilities can be exhausted. If so, it has dramatic implications for the X-Men's new mutant community on Krakoa, and so Xavier pushed until the Fantastic Four allowed Franklin to explore his mutant heritage on Krakoa. Franklin's clearly loved the experience, enjoying being part of the newly-established mutant civilization.
But all that comes to an end in this week's Fantastic Four #25, in which Franklin Richards finally uses up his powers. A mysterious cosmic being who calls itself Cormorant has come to Earth. According to Doctor Doom, it originates from a higher plane of existence, and it soon becomes clear Franklin is the only one with the power to hurt it.
There's just one problem; according to Mr. Fantastic, Cormorant is a "beyond Omega" threat. Within a matter of minutes, all of Franklin's power is gone. The Cormorant declares his respect for Franklin, conceding he did not believe anything on this plane would be able to harm it and prepares a kill strike - one that is fortunately interrupted by the Invisible Woman's force-fields. Stripped of his powers, Franklin does the only thing he can think of; he races off towards the Krakoan gateway to summon help. It is then that he learns the heartbreaking truth that, now he has lost his powers, he is no longer welcome on the mutant nation of Krakoa. The gateway will not open for him. Franklin's world - the new identity he has been shaping for himself - has come crashing down.
As shocking as this twist may be, it's actually an important clue as to just what is going on with Franklin's powers. The Krakoan gateway should have let him through so long as has an active X-gene; thus, logically, it stands to reason his X-gene has somehow deactivated. Presumably, his ability to rewrite reality has been backfiring, rewriting his own DNA every time he uses it. If that is the case, then it stands to reason Franklin's father will be able to help now - because Mr. Fantastic of the Fantastic Four is sure to pick up on that hint.