I don't think it counts as a boss battle at all, but the battle when you're fighting Elmdor and the two assassins on the roof. Oh dear, I remember one of my playthroughs, having saved just prior to it, going in and having Rafa(whom you have to protect) going first and then moving into range to be instantly killed next turn. I had to reload and try probably fifty times until she finally decided to retreat to the rest of my party. Was not a good time.