Sarah: Major plot change anyone?

So an idea popped into my head last night while it was storming outside. Strangely, this idea has nothing to do with storms but I always get good ideas when it's storming. I'm not sure why. I think it has something to do with the fact that I LOVE storms. Maybe. Who knows?

Anyway, I had this idea about a girl who goes off killing the Hellspawn, except in this idea they're just called demons. Anyway, the main girl still has angel's blood, but the Guardian calls her a Seraph, which is an Old Testament word for angel (roughly, it translates to "burning one"). Basically, she is a supercharged demon killing machine that has been prophesied for many years and has angel blood in her veins (like Zoe Lennox).

But the thing is, she's already known about her fate for some time but after some mishap at her old school in NYC, she moves to Applerose, Georgia. It's a small beach side town with more than a few unfriendly faces. When her new friend is taken by a group of zombies, she goes off the rescue her and comes in contact with a daemon (which is different than a demon. A daemon, in my head, is a half demon. So, basically, they still have a soul and aren't all evil but they can turn evil at any moment). He's a night hunter who knows of her identity as the Seraph.

Anyway, there's a lot more to the plot in my head. Here's my main issue: if I end up going with this story for Zoe Lennox (she will likely have a name and looks and personality change to go with it), I'll have to change the ENTIRE STORY. So the debate going on in my head is, do I go ahead and take from the Zoe plot or just start a new one all together?

What do you guys think?

P.S. Sorry if this is all rambly, it makes sense in my head. Hahahaha. :D