Spell casting, magic and fantasy!! Who doesn't like it? Well, I don't but it could be fun for others.. *looks at his feet and walks towards the corner*

More spells and individual abilities (passive or manually produced) could add a more interesting and personal dinamic to the game. We all have a chess board lets get something a little more weird and crazy!

although, setting a trap would be nice. I would love for commandeers to be able to lay in a minefield to blow up a happless enemy or put up a pikewall defensive obstacle against cavalry. something "surprising"

I think even giving units something a little more unque that is use controled... for expample you could reduce scouts movement 10 normally but give the the ability "out run" It would consume energy or lower defence but the scout would gain 2 or 3 squares of movement for a turn or two. It adds an element of variety to the game that would be interesting I think.

Energy could be recovered through devoting an action to "rest" another ability.