Book III of the Demon Squad Series.
A revolt in Heaven, angels fighting angels. Who better to mediate a peaceful resolution than the Devil's nephew, Frank "Triggaltheron" Trigg?

Don't answer that.

When Scarlett arrives at his door, beaten to within an inch of her life, Frank finds himself in the middle of a war as the Nephilim arrive to finish the job. With only Eden still standing, the battle for Heaven spills over and ravages the Earth with deadly storms. Amidst the chaos, Frank must find a way to end the war before the battling hordes of half-breed angels, vampires, and lycanthropes reach Eden and bring about the end of existence.

No pressure.