"Confident" Achievement. *spoilers*

[Deloessian]

Does anyone know how to accomplish this? I am assuming it means the final battle with Eric, since it is the only one that uses "allies." I tried to engage him for hours over the course of the game, since he becomes an obvious target NPC about 60% the way of the game.

I was unable to engage him until after recruiting every single Ally race, and when engaging, I can only proceed by using my Allies, one at a time versus each of his armies. There is no way that I can engage him without my allies, or with less than all the allies there. Am I missing something in getting this achievement? It is the only one I cannot figure out how to get. I've left a Save file there just so that I can figure out how to earn this achievement.

Can anyone shed any light on the subject, because after about a week of Googling for more info, I've found no answers.

Thanks in advance, all of you. Otherwise, love the game, despite the occasional crashes.