Into the Seventh Solar System

A heavy mecha is truly that - heavy. 

It is like a mobile fortress. It has two defensive systems that are incredibly tough to crack. The first one is the magical barriers which the mage pilot can put up. I don't have to explain much about these magical barriers. For as long as the mage has energy, the barriers would be up. And in a heavy mecha, the mage does not have to worry about spending his magical energy for offense.

The magical bombard enhances the mage's energy into powerful attacks. Which means that it has a very insignificant toll on the mage's magical reserves. Almost a hundred percent of the mage's magical energy can be directed into the heavy mecha's defense. And usually, this lasts a very long while. 

Once the mage's magical energy has hit the minimum level, the heavy will switch to its secondary defensive system. The Iron Dome.