A suggestion or a wishful idea.

Think about a Tank Job/Class that is a Disciple of Magic. Yes. It's a "WHOA?!" Factor.
There are lots of variations that could happen to this new breed of tank. I would play it and master it because this will stand out and it will be the first time (subjective) that it will happen in all of the MMORPGs.

A mage that specializes in defensive spells or summoning an armor to mitigate damage. Think of Gaara in Naruto anime. Would be so cool.

If you feel it too. Please add your ideas below!