I have such a complex backstory for him that is so far removed from actual game, I figured I would put him here, I'm proud of his design (❁´◡`❁)

He used to be a researcher at a laboratory overseen by the Ancients. He was kept in research positions to hinder his magic development- the higher ups where fearful of his dark magic (which had a tendency to cause things to rot if not used correctly). During an expedition to Halcandra, the research team was attacked, cutting their trip short. The team managed to escape, however Magolor was left behind, seemingly on purpose. This wasn't super surprising to him, but he was still hurt and upset.

He was left on Halcandra for years, teaching himself how to use his magic. Eventually he stumbled upon records of the Lor Starcutter and the Master Crown.
He wanted a way out- but more than that, he wanted to get back at those who left him to rot. After getting his hands on the crown though, he decided to take over everything else first to further show off his power. Of course, he doesn't ever get to see the Ancients or his people while having the crown.

I'll add more info later when I'm not lazy