Should I get rid of the demons?

I've recently decided to go back and pick up where I left off at the end of NaNo. I kind of ran out of steam at the end of the month and just stopped writing, and I'd really like to finish the story, but I'm not really sure where to go with it.

So far, my street urchins have made friends with a nobleman and been moved into his home so he can teach one of them magic, and a bunch of demons bound into human bodies have been trying to kill the duke's bastard half siblings. Because this happens to include one of the urchins, the plot has come to the attention of the nobleman and, through him, the duke.

With me so far? What I'm unsure about is the demons. Originally, it was just going to be a plot by one of the half siblings to kill off all the others and become duke himself. Then a couple of mages showed up, to balance things out a bit and give them more of a chance against my main characters. Then all of the plotters turned into demons and I have no idea where things are going anymore.

So, my question to you, oh wise and benevolent denizens of the internet, is this: should I keep the demons and try to work out what their goals are? Or should I go back and edit them out, and leave it as a plot by one of the half siblings? If it makes any difference, it would be quite a lot of editing, but I know I'm gonna have to do that eventually anyway. Or do you have some other suggestion that might work better than either of these?

Thanks

My advice? Just go with it for now. It might work itself out in the writing. If it doesn't, you can edit it out later.