From my observations 'fallen' just represents angels that have decided to come down to earth and help human kind and sometimes this can be quite daunting for them as they are so pure of heart and spirit.
They quite often refer to fallen angels in the disguise of dragon creatures. Dragons represent the highest spiritual power, the supernatural, and the spirit of change, when you align the forces with those of the dragon you gain strength and power but it is to the caller whether these abilities are used for positive or negative traits.
The dragon, lion, unicorn, e.g. most mystical creatures represent the bloodline and powers of fallen angels and with all these traits they can either be used positively or negatively.
KEY TO THE ABYSS/REVELATIONS.
With reference to the key to the abyss. Lucifer isn't the evil one. He is definitely a different angel from Satan. Satan has been bound for a thousand years according to revelations. Lucifer I believe takes on the burdens of the world he looks after and helps guide our hell on earth. Lucifer is known as the light of god.
Over the centuries we have been deceived by the greatest power on this earth since Christ's last coming and now this power is starting to crumble at its foundations.
The power isn't a person but a thought or belief that has persecuted the name of the truth and free will for thousands of years. We all are the light of god and he who follows his heart will see the light. The Holy Spirit is in us all.
The second coming isn't just one person I feel it is groups of 1000's of light workers already here on earth and in place awaiting for people to open their hearts to the truth, so the light can shine through. Just as the Lord gave us the four seasons so the Lord gave us an insight into our cycle. Presently we are in the winter but with the knowledge that the spring will be soon upon us, but as in winter we long for the spring even though we know it is just around the corner, some people don't get through the harsh conditions of winter they just aren't strong enough. Look at revelations in the same frame work. Be strong in the light, have faith and we will survive with the blessing of a brighter future.
Authors Details: Christine Williamson