[color:"orange"]won't the others be worse?[/color]
No, Josephine is arguably the most difficult opponent in the game. You might have trouble with a couple of the others, but generally speaking they should be a little or a lot easier.
You need to finish off all the Black Ring members before being able to reach the Demon of Lies, but doing the others before Josephine may be enough to let you get another level, or better equipment, etc. There are tricks in the topic above which can make it an easy fight, though, even without that.
