In the finale, when Railag says, "and who is this Shadia!", Biara replies, "I am Shadia!" (or something along those lines, I don't remember the exact words).
Well, of course, you see, you kill some guy, transform into him, and essentially become him. There would be an inconsistency if we assume that Shadia never existed.
P.S. Change Turis to Tarris!!!
