How does Frank come back as a evolved zombie rather than a bog standard zombie? Frank has been exposed to all forms of Zombie Vaccines/cures (the prototype vaccine which was supposed to last years if the exhibit in Dead Rising 3 is any indication, Zombrex 12 hours/24 hours and the Ramos Vaccine). His body has taken in all of them over a long period of time, but since the vaccines only suppress the parasite rather than kill it, his body was able to adapt and essentially assimilate the parasite. That way, when he died, he became something closer to Calder, but he kept most of his higher brain functions, probably more than Calder did based on their respective mental states.
