Far Beyond The World: Reverse World

Azazel - You couldn't defeat him?
Azazel - It's good that the central god spared you.
Azazel - I hope this punishment won't be too harsh.
Azazel - It's too early for you to die Caelan.
Azazel - You must defeat him.

It tells the story of what happened to Caelan from Humans Last Hope after the first battle with Omega.