James Islington: The Light of All That Falls: Book 3 of the Licanius trilogy

The Boundary is whole once again, but it may be too late. Banes now stalk Andarra, while in Ilin Illan, the political machinations of a generation come to a head as Wirr's newfound ability forces his family's old enemies into action. Imprisoned and alone in a strange land, Davian is pitted against the remaining Venerate as they work tirelessly to undo Asha's sacrifice - even as he struggles with what he has learned about the friend he chose to set free.