An Affinity for Steel: The Aeons' Gate Trilogy

From Publisher:

And the very lowest of these is to become an adventurer, like Lenk and his companions.

For the right price, no deed is too dirty, no task is too dangerous, no foe too ferocious. Not even a demon.
From wars ancient and terrible, wounds are bleeding. From seas deep and fathomless, demons are rising. From the mouth of hell, the Kraken Queen is calling. And all that stands between the damned and the mortal world are a pack of degenerates and the steel they carry.

Seas will rise. Heaven will fall.

Now, for the first time the breakout trilogy by Sam Sykes is collected in one volume.