First of all, I like what you've done with the magic system. However, too many of the spells are either useless, or become quickly useless because of a lack of scalability.

I suggest making spells scale with caster level. For example, the unit enchantment, "courage," is next to useless because it only boosts the unit's HP by +3 (+1 per life shard). This is not nearly enough HP. With a base such as 10 HP, PLUS, for example, 4 HP for every caster level, a level 10 caster would boost a unit's HP by 50 HP, which may or may not be a reasonable amount for the types of encounters and damage that is being dealt around that time.

Rather than making higher level versions of spells that do the same thing, just make them scalable!

What's up with intelligence? From what I've gathered, the only thing it does is spell resistance and "spell mastery," which determines whether or not your spell can punch through an opponent's magical defenses? That is a great idea, and I think it should be kept, as this keeps the balance of a warrior champion/sovereign from being able to damage a true caster-class champion/sovereign with magic. However, it just doesn't seem like enough at this point. I've really only been unable to damage one character with magic so far, and that was Magnus, whom I think gets +1 int/level.

Intelligence needs a little more of a carrot to make it useful. How about a reduction in mana usage by the caster? Int * .2 (20%) or some such equation to make intelligence truly a useful stat to have a lot of.