You need 2 good archers (Bashira and Spica should be enough), 1 vampire hunter (Khuri should be enough), 2-3 healers, 1 priest(ess) warrior if you're lacking in healing power, 1 heavy to tank the archangel, 1 valk to attack the angel halberd warriors, 1-2 ranged melee units. Basically I followed this guide:
https://www.youtube.com/watch?v=uMsReDrQ3mc . You don't need to have your units mincosted like in the guide. I did it with a 15 cost Bashira and a 14 cost Spica. After the initial deployment of 2 archers, Prince, 1 healer, and Khuri, you should be fine in terms of UP cost. Alternatively, you could use a mage (in your case Odette) in place of the vampire hunter. I 3* it with a level 50 Pallis before I switched to Khuri.