In the Old Testament of The Bible, “Lucifer” does not refer to the fallen angel. “Lucifer” (light-bearer)is a generic title referring to the morning star (Venus). As such, it has been used throughout history to refer to Satan, Christ, and others. With this in mind, Isaiah 14:12 starts out “How art thou fallen from heaven, O Lucifer, son of the morning!”. Taken as a separate verse, this appears to refer to the battle of angels – however, the PASSAGE starts at Isaiah 12:4 “Thou shalt take up this proverb against the king of Babylon” and towards the end is Isaiah 14:22 “For I will rise up against them saith the Lord of hosts, and cut of from Babylon the name, and remnant, and son, and nephew, Saith the Lord.” Thus Lucifer in the Old Testament refers to some unnamed Babylonian king.

Therefore  the term “Lucifer” is a translation mistake.