The word sibling doesnt necessarily mean your brother or sister, it can be used for parents too. Just thought you all might like to know.
A good chapter, it seems like Orochimaru's about to die if he doesn't reincarnate straight away, things are about to heat up a bit I think!
I wonder if there's a possibility he'll use Kabuto's body just to stay alive? That'd be kind of dumb though.