It is unknown when Akhnan became the shaman for the tribe. He was able to pass the Ordeal of Shamans, even though he was not incredibly powerful.
Akhnan was immediately in favor of execution upon meeting Alanna of Trebond and Coram Smythesson, and they fostered an enmity. She tried to get through to him a number of times, but he did not respond well. At one point, he attempted to make a Gate of Idramm, which would have destroyed the entire village, and perhaps the Great Southern Desert as a whole. The only reason he was stopped was because Faithful warned Alanna about his doings.
He later took the crystal sword and tried to kill Alanna with it. She created a shield that mirrored whatever spell he sent at her, so he was technically killed by his own magic. As Nazzir died while attempting to kill Alanna, she had to take his place as shaman of the Bloody Hawk, or leave the people unprotected in the desert.
He only appears in The Woman Who Rides Like a Man.