I have been playing around with the concept of rage for a while now trying to work out how to get a new resource and feature into demigod fairly. After a small amount of discussion with mithy, i believe it is possible.
The concept of this mod would be to:
At level 10 you can shop at a new shop and purchase a single ability (free --> these abilities are generic (same to all demigods) and purchasable off your demigod from the window described below.
This:
Adds a new mana bar which is filled up every time you strike an enemy unit (or are struck by one).
This ability has its own window on the ui bar. Using the ability will decrease rage. Rage abilities will have 10 sec cooldown provided you have the rage to use it.
Rage decreases over time and will return to 0 if out of combat long enough.
What do you think? Kinda like a second favor item but adapted to be an ability that uses a new resource.
Concept Art:

This would then give you a second chance at getting a unique set of abilities (like favor items) about 50% of the way through the game and IMO would very much enhance the strategic aspect of the game later in.
What do you think. Any feedback is useful. Would you use this mod?