User blog comment:CARTOONNETWORKDUDE/Chrono or Chroni/@comment-1622149-20120406220415/@comment-3549757-20120422010618

It was all explained in Ben 10,000 Returns. One of the Bens had unlocked the Chronian DNA sample. When he transformed into Eon, he lost control. So this means that Ben can transform into a Chronian, but he can also become a Chronosapien. It was all shown in Ben 10,000 Returns. Along with that, Dwayne had confirmed that there was still Chronian DNA somewhere in the Codon Stream, so that means it must exist alongside Chronosapiens.