User blog comment:ADour/ALL-NEW, ALL-DIFFERENT MARVEL's new titles revealed!/@comment-1895174-20150625212736/@comment-16461120-20150625213823

Since the arm gives the identity away, I suspect it's something such as the Techno-Organic Virus infection of Nathan Summers, the demonic corruption of Piotr Rasputin, or the severed limb of Thor Odinson.