Hand of the Black City (The Assassins Collective #1)

Trystan Süll is a Hand of the Iron Will, an emissary of the Black City sent forth with violent intent. He knows nothing of life without discipline and pain, nothing of love or sympathy. He is a living tool, carved of flesh and bone to deal out judgment upon the enemies of his masters. There is no place in the world you can hide that he will not find you.

Especially when you're the stragglers of a broken army, traitors fleeing defeat, having earned themselves the cold wrath of the City.