Akasha is a traitor monk who wants revenge on the Kougon Sect.
Akasha left the Kougon Sect after he killed his own Shikabane Hime. Since then he's been hunted to try and keep the secrets of the Kougon Sect quiet. Akasha wants to destroy the Kougon Sect for "betraying" him and teams up with the Shikabane group, the Seven Stars, to accomplish this.
Akasha's Shikabane Hime was actually his own girlfriend. He wanted her turned into a Hime so they could spend more time together. Shikabane Hime are told when they kill 108 Shikabane that they will go to Heaven. After Akasha's Shikabane Hime kills 108 she does not. Instead, she goes on a wild rampage killing everything in site. After she is stopped, Akasha is told that the 108 was a lie. Truthfully, Shikabane Hime can never go to Heaven, but they would never help kill Shikabane if they knew this. This is when Akasha leaves and swears revenge on the Kougon Sect.
Akasha with Hokuto
Later, Akasha betrays the Seven Stars and turns the Shikabane Hokuto into a Shikabane Hime and uses her against his enemies, including the members of the Seven Stars.