Shoko Asahara
Shoko Asahara was the founder of the controversial Aum Shinrikyo cult, which were responsible for the release of sarin gas into the Tokyo subway in 1995. It was believed that Asahara ordered the attack on the subway as part of a plot to overthrow the current Japanese government and appoint himself as Emperor - although according to Asahara's lawyers the event was masterminded by independent followers without his consent.
Regardless of the reality Shoko was sentenced to death but has had the sentence disputed several times in court, he is still awaiting execution and all attempts to reverse the sentence have been rejected by authorities.