Actually, that's not true.  They were actual seperate personalities, that
the main character came up with to replace the fact that his entire tribe
was destroyed.  Each one was based on someone he was close to.  Guardian
WAS his mind's recreation of his mother.  Bitter WAS a recreation of his
brother (I think).  The only one that was different was Master, who was
actually the "head good guy" communicating with the tribe.  In the end,
the tribe "moved" into the "head good guy"s mind, leaving the main
character alone.

I think Bitter was one of the older children Sorak played with...

However, there are differences in the way Ranma's tribe is presented.
It's fairly obvious that Bitter is in love with Nabiki, while Ranma is in
love with Akane.  Not only that, while Ranma is the core personality,
Bitter has far more depth than any of the other personalities.  I would be
willing to bet that an ending in which Bitter dies is NOT in the works.
(But then, I'm biased, I like Bitter)

My, my, my..... So much guess work going on... =)  The next 1 or 2 parts
should complete the story, so I guess we'll find out everything in a
couple of weeks.

-Anand