Earthbound Angels Trilogy

Oracle of Philadelphia:
Carrie works at a diner in South Philadelphia, dispensing advice to humans and angels wise enough to seek her counsel. But there are some problems that even the best advice can't solve. Her latest supplicant, Sebastian, sold his soul to a demon in exchange for his sister's life, but his heart remains pure. In order to renegotiate his contract, Carrie must travel into the depths of hell and parley with the demons that control its pathways.
Raising Chaos:
When Bedlam learns that the archdemon Azrael has escaped from the Abyss in order to wreak vengeance against the person who sent her there—Bedlam's best friend, Khet—he can't sit idly by. Only one relic possesses the power to kill Khet, who suffers immortality at Lucifer's request: the mythical Spear of Destiny, and Azrael claims to know its location.
Archangel Errant:
When Heaven is suddenly attacked, all the angels become trapped in their own nightmares. With Michael gone on an angelic mission, Gabriel must rally the remaining seraphim to rouse the sleeping angels and discover who seeks to take the agents of Heaven out of the celestial battle.