By which you mean...?
My avatar has to personally defeat the enemy without aid?
Yes, although the only confirmation i can find right now is in this
review @ GameBoomers
Here's the relevant bit:
"The way you gain level is as usual, through experience. This is not done with experience points however, but with a small “bar” indicating how far you have progressed. It takes time to gain a new level in this game...the bar moves very slowly, and it really makes you strive to gain a new level, and makes the wait all the more worthwhile.
To gain experience by defeating foes, you have to be the one defeating them. I do not see the point in having an army at your back, but not letting you gain experience for the enemies your army kills. After all, they are bound to you, and therefore should not their experiences connect to you in some way? The current game structure means you have to be at the front of your army most of the time to gain as much experience and power as possible, and not in the back, where it is relatively safe – an important factor if you are a mage. In Spellforce you do not actually have to be as powerful as you possibly can, since much of the time you can have an army do your work for you. But it is very helpful to be somewhat powerful on the maps where you are only accompanied by your Heroes."
I don't know about the 'without aid'. I'm thinking its more your Avatar had to deal the finishing blow maybe...