I'd personally do it like this:
[-1]Incite Emotion - Fear
plus: [-1]At Range
[-1]Zone wide (same zone only) - House rule
This would allow the demon to use this as a manoeuvre on a everyone him all at once. If you want it to be an attack you can add on lasting or potent emotion, but this would still not be 'always on' and that should really cost another refresh to do zone wide (IMO).
This is a house rule though, others may do it differently.