I would like to see something's such as a shared Dmg ability where you have to group up to take a hit or tanks having to tank either beside or in a line to take certain moves or risk a really heavy hit. I would say playing on a class or two like a pally infront of a warrior to part a magic attack and then the warrior there to prevent a big heavy weapon coming down on the pally 's head

I really like that zombie idea would change things up a bit and sticks to the ff gameplay mechanics