Think about it. Lucifer is a Latin word. The Old Testament was written in Hebrew BEFORE Latin became a language. It's a poor translation accompanied by hijacking of the original Biblical story to try and fit in a character that rebelled against God. No angel of any choir or tier has ever rebelled against God. They all do as he commands. More on that in a minute.

Biblical scholars believe that the chapters in Isaiah referring to the fall of "Lucifer" was actually using metaphor to describe a historical Babylonian King, equating him to being like the morning star, or Venus. The serpent in the Garden is also never directly attributed to be Satan, only inferred since that's what they describe him as when he fell from Heaven. Some attribute the serpent to being the Angel Samuel, though this is never actually stated in the Bible.

Michael, Raphael, Gabriel, Israfel, and Azrael are the only named Angels that are ever actually named in the scripture. Others were named later in other texts.

The implications of this mistranslation are... huge. It means that if there is an evil force in our universe, it is not a fallen angel of God's but a primordial force that may be as old as God. The Darkness as it were. God created light and order out of darkness and chaos, but that doesn't mean he eliminated it. In scientific terms, God works against natural entropic forces of the universe, and thus our duty as his creations is to do the same. To uphold order and the light against darkness and chaos.

It may also be true that God sends his angels to tempt us regularly in order to weed out the weak from his Kingdom, while the rest are doomed to either spend eternity in hell, or have their soul recycled in order to make another go at it. Some also say there are a limited number of souls available at any given time, and many who are alive today don't possess one, and those are what we know of as NPC's.