Ruled by Steel. The Ascension Series, #3

Only a demon can save the souls trapped in Hell. Elise Kavanagh failed to prevent the Breaking, and now Hell is spilling onto Earth. She's delved deep into the City of Dis in an attempt to stop the infernal armies-but even the legendary Godslayer is unprepared to face Dis's fiercest demons, not to mention the responsibility of liberating the humans they've enslaved. On Earth, rogue angel Nash Adamson is wing-deep in damage control after the Breaking, and his fellow angels don't want to get involved.
War is approaching the werewolf sanctuary. If Heaven won't help them, he'll have to turn to Hell for salvation. Everything hinges on who can control the Palace of Dis. Elise and her allies have no choice but to rule by steel.