I made a post about time mage a while back and ast is usually the rebuttal, but I considered it for the tank role(from ff12 zodiac age time battlemage) pretty much the same thing as what ur saying but using the time magic to negate damage from hitting you as much. Time magic is one of my favorite FF magics because of how useful it can be and I'd love to see a full on time mage regardless of what role it's put into.