User blog comment:Observer Supreme/The Gorosei's Role/@comment-3529684-20161228044251/@comment-3529684-20161228053941

yeah just like germa 66 naming sense. But still, there are rumours floating around that the gorosei is immortal.....

Theory below.

They cannot be harmed in anyway or even killed unless one piece is found. I believe the treasure "One Piece" contains an accessory that can kill off Goroseis. Roger and his crew left it because they don't know how to use it lol

And i believe Raftel can only be accessed by people holding the will of the D.