Hmm, interesting idea. I imagine that writing magic into the Twisparkle universe could be difficult - the author needs to be very careful to keep the character from god-moding (Sparklepires are god-moded enough, as it is). Two pieces of general advice I'd give:

- Try not to announce time jumps with stock expressions like "in the morning he did this", "in the evening someone called him" or "one day he was in the woods", because it could be a little jarring. Introduce time jumps with less standard sentences, say: "It rained throughout the night and most of the morning, but that didn't stop him from going into the woods", "His supervisor's voice was clipped - she called him in the evening to find out how the investigation was going", or "The morning turned out to be quite productive - he was working his way through a bowl of cornflakes when an idea hit him".

- We still know next to nothing about Durin (other than the fact that he's a wizard and has scars). He seems to go into a sort of suspension mode when he's not around the Twilight characters. What are his habits? What's about his personality? What does he like and dislike? He's supposed to be a murder investigator - show him wandering around on his own, looking for clues, asking questions, at least a couple of times, so we could relate to him as a character.

Good luck with the story!