Archangel Michael heads up an Angelic team which oversees the roles of Angels. Some Angels have been described as fallen Angels. In reality, this is not a true definition. Just as to label something good or bad, would be based on a subjective perspective, or on your level of spiritual attainment.
Angels are messengers of God and as such undertake to work, teach and love unconditionally. This is in line with the Divine Plan or God Mission. However, an Angel may decide not to undertake the work of God.
If this is decided by the Angel even after their initiation into the Angelic realms, then the Angel is no longer able to stay. The Angel has now chosen to work in other realms of existence.
The Angels that leave the Angelic realms have chosen to have free-will. As such these Angels have a choice how to act in their lives. They now have a choice how to react to life’s lessons. They have free-will in the same way that humans have free-will.
To have free-will is to forfeit the Angelic Realms. Free-will means that you now operate with ego as one of your driving passions.
Ego helps us to respond quickly to situations, it helps us to compete and aspire to new levels. Ego has to be carefully balanced with compassion and love.
A fallen Angel is effectively someone who has chosen to leave the Angelic realms to experience the workings of choice. They may not have successfully balanced the attributes of ego and unconditional love. This can lead them to make choices which would not reflect the qualities of unconditional love and non-attachment. The qualities normally attributed to Angels.
Angels serve God
Angels are messengers of God
Angels have pure-souls and work only in the realms of Unconditional Love
Angels are made of the Divine Essence of your God , Source, the Divine
Angels have no free will