I'm having trouble finding a source of motivation for my villain in my story. I've decided why she's the villain and that my protags what to stop her because eventually, she'll get to their own universe, but I don't have motivation for her. She is basically this 'demon god' type thing and her goal is to annihilate all the universes and after shes finished with one, she moves onto the next. I just don't know exactly what her motivation for this could be. Any suggestions?
This sounds like "The Society of the One World" that I have going on in my multiverses.
You may want to study up on karmic theory and samsara to see how you can write destruction as something that can be viewed as peaceful or liberating. This demon may not be evil - in fact, she might actually have very good intentions! It's just…you know. Destroying universes without the occupants' consent is not the best way to go about it.
You could also think of a way to make her not seem so much as a villain in the reader's eyes by giving her a good reason to do what she's doing.
Possibly she could have to do it and it not nessaerily be a choice. Like maybe insted ofdestroying them she culd comsum them like she has to or she will die
I've had the same issue with writing my villains, and I think that the best place to start is their backstory. Motivation doesn't just happen out of nowhere. Think about who she was before your story began. Build off of that and keep going.
A motivation for something like that doesn't always have to be complicated or redeeming for the villain. Something that could work is simple desire for power, or maybe simple satisfaction with killing. Psychopathic villains can still be just as interesting as sympathetic villains if written right. If you want a more sympathetic villain approach, however, it could be that by destroying the inhabitants of one universe she is saving more, or her family, or herself or something.
She wants to be important.
Like Owl Man in Justice League Dark, your villain wants to be the only person to have ever done something truly important in all of existence.
She couldn't deal with just being 'another person' who is born, lives, and dies without doing much. She just wants to have done something by the time she dies.