Aquila Series by Gordon Rennie, Leigh Gallagher, Patrick Goddard

He was one of the rebellious gladiator-slaves crucified by the Romans for being part of Spartacus's uprising, and in his dying moments he called out to the gods for vengeance. Something heard him, and brought him back from the dead in exchange for his soul.69AD. Aquila was a slave-turned-gladiator who was amongst those crucified following Spartacus's failed revolt... moreHe was one of the rebellious gladiator-slaves crucified by the Romans for being part of Spartacus's uprising, and in his dying moments he called out to the gods for vengeance. Something heard him, and brought him back from the dead in exchange for his soul.69AD. Aquila was a slave-turned-gladiator who was amongst those crucified following Spartacus's failed revolt. Dying a slow death, a Roman eagle carved into his chest, he cried out to the gods for vengeance - and Ammit the Devourer answered, offering him invulnerability in return for delivering to her the souls of evil men, for which Aquila hunts the breadth of the Empire... less