Cliche? Angel switching sides? I don't know where you got that. I'm not insulted, by the way
I did switch up a lot, but that was due to Lunaster's quite confusing history.
Okay, I did have parts that were cliche, though. Those being... Um? Oh! The four elemental planes of the Djinni surrounding the materia "human" plane. Then there were four planes of light and four planes of darkness. Lunaster existed on the highest plane of light.
The "love of his life" dieing wasn't too cliche, to my knowledge. Also, Lunaster never "switched sides". He betrayed Heaven, yes, but that was because he sought to take revenge on his loves death. He never
wanted to become a demon. Also, he only became a sacred demon. That is a "half-fallen" angel. At that point, he was made into a weapon for the new, who became the "true", Lunaster. He then had his soul removed to prevent such an even occuring again, and the soul of his love was then added to Lunaster's soul and placed into his second "weapon".
Bah... I shouldn't have to explain this, really. If you notice, I start with just high-level soldier. He begins one of the weakest "types" of angels, and an archangel is created to replace him. He's no general; though, he becomes a "lone" acting archangel.
You may want to try to understand what is written before you "judge" it