The original hierarchy of heaven:
God, Jesus, Holy Spirit
Archangels - Lucifer(12 wings), Michael(has no wings)
Seraphim - Gabriel, Azrael, Raphael, Uriel, Raguel, Sariel, and Jarahmeel
Cherubim
Angel
(the first 3 - Lucifer, Michael, and Gabriel are considered cannon, Raphael is mentioned in the Tobit, the last four are mentioned in the book of Enoch)
It is unclear which of the seraphim(if any) mentioned in the book of Enoch joined Lucifer, but the two most high-ranking angels who joined Lucifer changed their names to Asmodeus and Belial.
Angels are created as an extension of God's will and as such were dependent on God's power like leaves on a tree. Without God's power to sustain them, they were destined to die. Many of the smaller angels were died out or went insane after being cast out of heaven. The stronger ones were rendered incorporeal and unable to interact with the physical world easily. The only way for a fallen angel to survive is to convince a human to give up his life force willingly, after having understood the folly of such a decision.
Lucifer at great cost, used up much of his remaining life force to materlise as a snake to deceive Eve. After the fall of Adam and Eve, Lucifer then deceived their son Cain. Cain killed Abel and was cursed to wander the earth. In desperation, Cain turned to Lucifer for help, offering part of his life force in exchange. Together, they in turn deceived another of Adam's descendents to further the line of Cain and spread evil in the world.
It is interesting to note that before the flood, the appearance of this pact between Cain and Lucifer was one of master and servant. Cain and his descendants were very much stronger physically than Lucifer, however Lucifer ultimately had the upper hand of the unwise Cain.
With the spread of Cain's descendants, a race of super beings foolishly supplying the fallen angels with life force in return for imaginery help, God had no choice but to destroy the antediluvians with a flood lest Lucifer and his minions became too powerful after incessant feeding. The situation was nearly in-salvageable at that time with the whole world providing feed to Lucifer and his minions with the exception of Noah and his family of eight people.
After the flood, God wisely limited man's life force to no longer than 120 years. This was done with good intentions and has brought about many benefits for the human race. The chief advantage was that, having a shorter life span, man was far less likely give out his life force to any of the fallen angels. During this period, many more fallen angels died out until the humans multiplied, forgot and became susceptible to temptation again. Angels cannot replicate, thus any angel that dies is a big blow to Lucifer's cause.
God's decision has bought the human race four thousand of years thus far. Conversely, with the multiplication of human's in the world. The number of people who willingly give their life force to Lucifer has also increased greatly.
Whether the benefits of time extension has been exhausted today is of no consequence in God's eyes. If even one human still has the chance to repent, the world will not be destroyed. It will continue until humans make the world uninhabitable themselves with their pollution.
However, Lucifer has a time limit to force a final confrontation. This is because diluted life force is no substitute for those harvested from the antediluvians. His power is wanning gradually no matter how much he tries to conserve it by relying on humans to do the work for him. There will come a time when the benefit of gaining more followers cannot make up for the disadvantage of losing more of his power. He will be forced to plunge the world into chaos sooner or later and take as many people with him.
For reference-
Michael is the form God takes occasionally. As God does not like to exhibit his power openly, Michael is listed as less powerful than Lucifer in the original hierarchy. Jacob(a human after the flood) was able to fight Michael on equal terms in a contest of strength.
However, after Lucifer became a fallen angel, he lost much of his power. Even after six thousand years of feeding, he probably is still weaker than the weakest cherubim. Although he more than makes up for that in terms of intellect and cunning which were interestingly not lost when he was cast out of heaven.