The lore is actually unclear on that. Most seem to agree that Lucifer is a fallen angel, but it's never so much as suggested in the source material that Satan is Lucifer. Lucifer is actually only mentioned one single time, in an old testament verse. The other dead kings are making fun of the king of Babylon for failing to defeat God and dying himself. As the king of Babylon is dying, the other dead kings say he has "fallen from heaven" and call him Lucifer. It seems implied that Lucifer and/or the king of Babylon are being compared to ~~the sun~~ Venus, the "morning star", and the second brightest object in the sky behind the moon [added this part in an edit], and I think many have interpreted this as to mean Lucifer was an angel that tried to shine brighter than God and this was cast out of heaven. But it seems like most of the modern depictions of Lucifer have no basis in biblical canon. It's all people trying to extrapolate from one single time the name Lucifer was mentioned while dead kings make fun of a dying king.

I mean I feel like undoing all creation every time I fall or stub my toe, too. Sure, we all do. But geez, it's a figure if speech! An in the moment thing!

"anti" also doesn't mean opposite, it means against. The roots of the word, tracing back to the Greek, means against. As it does in French and it's Sanskrit version. All forms of it mean opposed to. This is why language is important and some checks should be there to counter the "language is malleable" argument that people use as an excuse to not learn how to use words correctly. The idea that anti means opposite has been around as long as I can remember, and definitely longer than that, but it drastically changes the meaning of words.

Satan and Lucifer are only the same being in the minds of theology invented by men, in the Bible they're never mentioned as being one and the only time ha-satan is mentioned is in the book of Job, which plays out in the opening scene like a formal hearing where the accuser (the meaning of the word Satan) is investigating God to see if he's made a worthwhile creation or that his creation will worship him.

He says that there isn't anyone on earth that would worship God unless they were actively protected/blessed by God, which is the accusation against God and his creation. God then retorts with a "witness" of sorts in the courtroom of divine beings, claiming Job will prove Satan incorrect.

Then the events of Job getting his whole family killed and losing everything occur, etc.

It's just funny how modern fundamentalist Christians see it as some kind of "bet" between God and the devil, when the text makes it seem like God is on trial and Satan is the prosecuting attorney assigned to the case. Never does it imply that he's Lucifer or the talking snake from genesis, and the Bible never conflates those two characters either. That's exclusively been done as part of the theology surrounding the Bible that has been taught for so long to people so young that they believe it's just part of the faith, and since most will never bother to read the whole Bible they'll just assume it's true and go on acting as if it's in the text instead of a very VERY loose conclusion drawn from the Bible.

If only he had life link...

Still he is often portrayed as the evil counterpart of God, which is as opposite as you will get