Redemption by Nikole Knight

Riley is missing, and it’s up to his angels to find him.
With help from their allies, Gideon, Jai, and Noel fight to locate the missing piece to their family—and their hearts—before they lose him forever. Realms will topple, and worlds will burn. Because they will not stop until they get him back.
But for Riley, time is running out.
Trapped in the cursed realm, Riley Shepard finds himself at the mercy of the Seven. With no friends and no hope, he struggles to survive the horrors of Hell as he battles the inevitable pull to the darkness residing inside himself. But one way or another, he must face his demons or die trying.
If only death was so easy.