A non-DBZ thread is not only a breath of fresh air, it's a sign of hope for humanity.
Hiei solos. He's much faster than Mihawk and Byakuya, can take hits from Sensui and Mukoro (Who are both easily above anyone from One Piece and Bleach in power), can melt bladed weapons as if they were chocolate bars with his yoki, his Jaou Ensatsu Kokuryuuha is not only powerful but can chase after his opponents, and his destructive power trumps Sensui's by the end of the series. Feitan isn't required here.