Thor was one of the strongest battle-type gods to ever exist.
Ever since he earned that title, his hunger to become stronger grew to an otherworldly level.
He did everything he could, and everything he was able to do, to grow stronger, and the path he chose turned him into a ruthless and blasphemous god who didn't care what he did as long as he gained more power.
A few thousand years ago, some of the dark elves from Svartalfheim stumbled upon a very unique and strange artifact, one they couldn't use, as it was beyond them, something even gods would grow greedy to possess.
But somehow, the elves accidentally activated that artifact, and when they did, it sucked every ounce of life they had, killing hundreds of dark elves.
That was when the Norse gods took notice of the dying elves, and that's how they came to discover the [Law Forger].
They didn't know where it came from, how it ended up in Svartalfheim, or who created it, but they did discover what it could do.