That is just not true. You can dominate the prison with a fresh save no problem. Obviously it is much easier with NG+ but that doesn't mean you can't with a new save.because most of the builds are precluded.
you don't have any possibility to fight at all because the lack of raw stats, advancing only as an hopeless slut
The true charm of this game, is about slowly learning how to gain strength, before falling.
Than trying again, with the new titles and knowledge accumulated, and in end totally dominating that hell hole.