Azulmagia was the most difficult solo fight I've done thus far, even knowing exactly how to do it courtesy of Mrhappy. That did surprise me because I would have expected to have the most trouble with a higher level msq duty, not a random job quest. Sometimes for whatever reason a certain encounter is just hard for me though (level 50 whm comes to mind) and I haven't tried Siegfried yet. I'm a little scared to, actually.