I like the idea a lot. I'd like to throw in my idea too.

A limit break mode. Something different for each style of combat. Either mage class or fighter class. This is how I think it should work. You can hit Limit break after taking a certain amount of damage, or doing a certain amount of damage or killing a certain amount of enemies. After breaking your limit you have access to super abilities, spells or attacks exclusive only in limit break mode.

I think this is a great idea^^