Add casting animations to castle magic. Including every school's version of it (EX: Storm, Moon, Shadow, etc). (Casting animation: The animation that appears in front of the wizard when a spell is being cast in battle)
Add castle magic that can make a player emote. (Dance, clap, floss, etc)
Please allow us to target interactive items with castle magic. That could be used in so many cool ways. (Like roller coasters)
A special mannequin that can automatically identify the attire of the nearest wizard and copy it. It would just be visual, and would not allow the owner to actually take that gear off the mannequin. (Chromatic mannequin)