Mai Mizuki

Mai is a S rank warrior who uses big black sword that is called the Death Sword since it can cut anything and has superhuman abilities. She was a ruthless warrior who had tormented a lot monsters. She was able to kill a demon dragon ( a S rank monster), who could destroy a entire continent with one full energy blast. Mai is in the clan of Mizuki where she could earn a special power called the Blue fire that could destroy a entire city.