User blog comment:Suriken88/Ezio's speculated death in Embers/@comment-124.6.181.90-20140317093916

That guy was probably the bastard son of Ezio and the ancestor of Subject 16. The man was tracking down Ezio, since he was his father, and he was probably fathered by Ezio during his wild youth (probably why the man commented on the women of Firenze). Subject 16 had an ancestor through Ezio, a bastard, and Desmond through Marcello/Flavi, hence the cousins part. All in all, the young man was Ezio's son.