Seems strong, I don't really have any good suggestions, so +1 it is

The one thing i dont understand are the 2 Mayor of Avabruck. Have you ever thought about Elder of Laurels? This is just my opinion, its pretty solid as is. +1 good sir

Oblivion Ring over Arrest . The ring can get rid of creatures or planeswalkers or enchanments. So much better at the same mana cost.

Oh and try to put in Rancor somewhere. It only helps.

I really like this deck idea. I am definitely interested in hearing how effective this deck is for you. I really like the idea of the detain mechanic. I feel like it could cause your opponent to really frustrated as well as clearing the path for a pumped up Champion of the Parish . A card you may consider adding is Inaction Injunction . It is a good way to slow down your opponent as well as get card draw. Perhaps if you need to drop a couple Gather the Townsfolk for it? Perhaps even Cloudshift to combine with Fiend Hunter to exile two creatures. A good blue card I would keep in mind for this deck is Arctic Aven . I think this card will be used a lot in the Azorius guild due to is getting the +1/+1 effect and possibly having lifelink. I would also consider +1 Mayor of Avabruck  ^Flip and -1 New Prahv Guildmage . The +1/+1 to all your humans is a very nice buff and I personally would want to draw him every game because of it. The only thing I really would be worried about is mass board clearing. card:Judge's Familiar in the sideboard for Doomed Traveler would probably be a good idea. +1 and keep my posted on your success!