The Archcrusade: Tome One:Archspawn - Pilgrimage & Propheices in Bloomington, MN

When bloodthirsty, parasitic creatures break their species' treaty with humankind by raiding the birthplace of the first archangel, the High King calls for a crusade in retribution.
Basil, a sheltered healing mage's apprentice, marches with the crusade in support of his Low King's hidden agenda: to seek an oracle's wisdom and gather insight into the fate of the realm.
During his quest, Basil faces threats from natural disasters, covert assassins, and insidious demons. Though Basil's master attempts to spare him from unnecessary suffering, Basil's desire for adventure lands him in life-threatening danger as he begins to unravel the truth of his divine destiny.