If I was one of the celebs, I'd want a paso or a tango for Halloween, as best suited to the mood and the drama. Georgia's tango has got to fight the music, imo, so that's tough for her. I think Kellie will have a great night as Kevin's got a good track record for the paso, Harry Potter's a great theme to have and Kevin's never happier than with a ton of props and drama and will throw the kitchen sink at it. Katie will also have a good night - I think the pasos have the best themes to work with - but Kellie's looking better in training footage (for what that's worth).
Or it could go the other way and a simple ballroom to dreamy music may contrast with all the busy, silly dances and everyone will love it, and waltzes also tend to score high, so Anita could have a very good night. Or Peter could - we haven't really seen him do a slow ballroom before so we don't know. Anita's going to look amazing and we don't know what Peter's theme is yet, or I don't think we do?
Jamelia could also have a good night.
Jay always has the potential to be great, but I think this mix - props, lifts, performance and ballroom - are a lot of hurdles for him.