Warning: contains spoilers to Marvel Zombies Resurrection #4!
One of the chief mysteries in the latest Marvel Zombies series has surrounded Franklin Richards. He and his sister Valeria were the only surviving members of the Fantastic Four family, and the series constantly teased the lingering mystery regarding his lack of powers (and signs of aging) in a world overwhelmed with hungry, super-powered zombies. Thanks to flashbacks from his current guardian Peter Parker, readers learned that the reason for Franklin's changes in this post-apocalyptic Marvel world is that he's no longer human, but actually a member of the techno-organic species called the Phalanx.
First appearing in Uncanny X-Men #305, the Phalanx are a techno-organic alien species which regularly assimilate sentient beings into their collective consciousness, the goal being to consume the entire universe in order to complete the hive intelligence and eradicate any threat of destruction. The Phalanx go from planet to planet, judging which species will be destroyed or assimilated into the hive mind. A renegade Technarch called Warlock rebelled against his species and has lived on Earth for years as a member of the New Mutants, and the X-Men have had many notable encounters with this species, helping to prevent the Phalanx from assimilating Earth.
In Marvel Zombies: Resurrection #4, Phillip Kennedy Johnson and Leonard Kirk finally reveal the truth behind a mystery they've been hinting at throughout the series. Through Peter's flashbacks, readers learn that Valeria and Franklin were reunited with their infected parents and the rest of the Fantastic Four, who willingly infected their son. After Peter escaped with both children, he pleaded with a group of surviving heroes to help him save the infected child, which they begrudgingly agreed to do. With Franklin dying, a combined effort from Doctor Strange and Warlock was able to transfer Franklin's consciousness into a Phalanx body, which his zombified mother learned when she attempted to re-infect him. The zombies even consider Franklin to have been "stolen" from them - something they previously thought impossible.
Considering Franklin's former reality-altering powers, this could be seen as a huge downgrade, but his status as a human-Phalanx gives him a huge advantage in this zombie-infested world. He doesn't age, he can't be infected with the Hunger Cosmic, and he possesses the ability to shape-shift. Thanks to Peter's intervention, this kept Franklin's Omega-level mutant powers out of the Hunger Cosmic's hands, which would have tipped the scales in their favor on a universal level. Adding his ability to wield Magik's Soulsword, this version of Franklin Richards is now a prominent threat to this incarnation of the Marvel Zombies. With the support of his sister and his new adopted family, Franklin Richards could be quite the monster hunter, should he live long enough to get the chance.