As a note, while it is possible for an angel to regain their archangel status via the past life regression, it is [I]extremely[/I] difficult for the reasons stated above. If not clear enough, well let me put it like this. Often the angel's more or less human body will crash due to the strain put on its essence by the increasingly pure and potent angelic essence as the angel recalls their past lives. While there can be/are ways around this, it tends to be quite difficult for you to get through the entire 7000 years of the angel's existence and back to archangel status.

In season one, my character, Saella (who was a tamer angel) managed to get through the majority of her past lives because she had the assistance of several demons (which she had tamed and was controlling to varied extents) to keep her mind and essence stable and allow her body to properly adjust as she regressed/regained her memories. It was in no way a painless process....