I need help developing/creating a BBEG!! (A villian) /u/Ill_Soil1131 DnD: Roll for Initiative!

So basically what I’ve been setting up is more or less dimension travelling dnd, more or less certain magic let’s the pc’s travel to certain worlds. They all started together not knowing how they got there! I’ve had them in various worlds with each one being more or less a long one shot, they’ve all had villains and npcs they’ve brought with them (well they’re still a little before this point but this is where they’ll end up) I also wanted to mention that above all these dimensions are like “super gods” not the actual name but instead of being the god of death, there is simply the embodiment of death (who is incidentally a really calm, emotional and living being with like a porcelain mask and anyway, ADHD SORRY) and the embodiment of life (a sadistic collected asshole more or less because life is cruel in nature kinda thing) are the main 2 I’ve thought of.

NOW; I want the villian to have been imprisoned by these embodiments in between all the dimensions for something and his escape or breakout caused basically collateral that bumped the pc’s into the same dimension, also becuase the players don’t belong in the worlds they travel to the universes are basically trying to kill them by dropping them into worlds full of conflict! Sorry for all the yap but the gist is villian idea! It doesn’t have to be molded to the above!! Also please be nice this is the biggest campaign idea and the first really big one I’ve fully written and dmed myself and I’m doing my best I’m jsut really stuck on this BBEG!

So basically what I’ve been setting up is more or less dimension travelling dnd, more or less certain magic let’s the pc’s travel to certain worlds. They all started together not knowing how they got there! I’ve had them in various worlds with each one being more or less a long one shot, they’ve all had villains and npcs they’ve brought with them (well they’re still a little before this point but this is where they’ll end up) I also wanted to mention that above all these dimensions are like “super gods” not the actual name but instead of being the god of death, there is simply the embodiment of death (who is incidentally a really calm, emotional and living being with like a porcelain mask and anyway, ADHD SORRY) and the embodiment of life (a sadistic collected asshole more or less because life is cruel in nature kinda thing) are the main 2 I’ve thought of.

NOW; I want the villian to have been imprisoned by these embodiments in between all the dimensions for something and his escape or breakout caused basically collateral that bumped the pc’s into the same dimension, also becuase the players don’t belong in the worlds they travel to the universes are basically trying to kill them by dropping them into worlds full of conflict! Sorry for all the yap but the gist is villian idea! It doesn’t have to be molded to the above!! Also please be nice this is the biggest campaign idea and the first really big one I’ve fully written and dmed myself and I’m doing my best I’m jsut really stuck on this BBEG!