Raiha, it seems, is one of the good guys in the Uruha. It also appears that he's the coolest character in the series.
Raiha's magical weapon is the Raijin which can control thunder. It must be some strong weapon but we never get to see him use it because he directly retreated in his fight with Kurei (I don't know the exact reason why). He was the one who rescued Aira and Max from the trap pit they got into, and subsequently told Aira that his weapon is the counterpart of the Fuujin and that hopefully the time will come that they will have the chance to fight. (Love affair or what?)