The fantasy genre is one I have not read widely in, so you can take my comments with a grain of salt. That said, any work of fiction needs to hang together and engage the reader on its own merits, genre conventions notwithstanding.
My response to Guarding Angel is mixed. On the positive side:
• The prose is clean and well crafted.
• The created worlds of Earth, Heaven and Hell are reasonably convincing, to varying degrees. Earth wins this prize, with its scenes and characters alive on the page.
• The characters (humans, angels and demons) are well defined and their interactions make for a coherent plot narrative.
• The story flows consistently around its themes of desire and conflict and reaches a satisfying conclusion that sets the stage for the sequel.
On the negative side:
• Originality of imagery and scene often gives way to stock cliches. Heaven with its robes and quills, Hell with its vague sulphurous caves; and rather arbitrary transitions between them.
• The middle of the plot drags through repetitive scenarios and dialogue; for example the obligatory teasing kiss shared by Enael and Kaspen, with its ever-delayed consummation.
• While in fantasy all things are possible, here too many shortcuts appear, more than once with the voiced excuse, “I don’t know how this works, it just does.”
The latter phrase might summarize the book as a whole. The vision is vast and well conceived, if sketchy at times. The themes are wide and deep: destiny on a personal and historical level; conflict between personal attractions and duty to others; free will in the context of karmic choices and life lessons.
The real strength of the book is the ingenious way in which the passions and needs of the naturalistic human characters parallel the interpersonal dynamics of their “Guarding Angels” - chiefly the main characters Enael and Kaspen. At its best the book compares favorably to Poul Anderson’s epic The Boat of a Million Years,” with its cycling of immortal souls through innumerable lifetimes, each depicted in turn through history, and encountering other reincarnated characters along the way. The drawback of this plot model is its episodic nature, causing the reader to become invested in one set of characters and scenes, only to have it go “poof” (like one of the imaginary creatures of the dark in this novel, the Fearlings) when the director calls “cut.” On the other hand, isn’t that what happens to us in life?