A good card recommendation for this deck would be the
spectral shepherd. Reason being his bounce effect would work well with
rattlechains and would allow for you to
reset a lot of your spirits in order to re-trigger their effects (and save them from being destroyed by Avacyn). Also two other things:
1) If your deck is White and Blue the color code for your deck is W/U not W/B (the B stands for BLACK and the U stands for BLUE).
2) What is the overall goal of your deck and what methods of achieving that goal have you built into the deck?