I think this thread ought to be renamed "Discussion of Any and Every Topic Under the Sun Other Than Cassandra Pentaghast." Geez.
On the subject of Cassandra's personal quest (assuming she does indeed have one) I don't want it to have anything at all to do with Galyan, or with Cassandra's brother. I'm tired of female characters (not just in video games, but in media in general) always being defined by their relationships with the men in their lives or in their pasts. It sends the message that women are only important if they're some guy's sister/lover/wife/daughter/etc, rather than presenting women as full-fledged characters with importance and agency of their own.
Not to say I would be averse to the brother or Galyan being mentioned in a conversation or two, but to have a whole quest revolve around them? No thanks.