To me, the most dangerous characters in the series are either, Hades, Percia, or Jail, or any mad scientist in perticular. Given how Hades wants to change everything by making magic impotent. Percia, her motive to save her daugther, Alicia, by using the power of the jewel seeds to travel to Al-hazard, she would do almost anything to achieve her goal no matter how destructive the results. And Jail, his intention to use the cradle for his own goals(I am skeptical with his goals, I have this itch that tells me that his way of being a villian is faulty and missing I just can't place it, even if his plans were unethical).