RE Cerberus Vents, Cerberus = three-headed dog who guards the gates of hell. Cerbreus' mother and father were Echidna and Typhoeus. Zeus destroyed Typhoeus by sealing him under Mount Etna but allowed Echidna and her children to live as a challenge to future heroes.

It would makes sense that Ben could be in 77, too. He's on Hydra so he'd never run the chance on bumping into himself. Also he told John at Orchid that he (Ben) could never return to the Island. Presumably he stays on Hydra. It also makes sense that as a 12yr old (or whatever) he falls in love with Juliet in 77. …