First, let's start off with this, which I am sure we are all aware of.
A barbarian who becomes lawful loses the ability to rage and cannot gain more levels as a barbarian. She retains all other benefits of the class.
Pretty self explanatory there, but what happens when an Ex-Barbarian multiclass into the Ulfen Guard prestige class, and most importantly, does the ex-Barbarian/Ulfen Guard retain his rage rounds from his ex-barbarian levels.
in this case, you are incorrect.
No, Rage rounds from different pools do not stack.
A theoretical character who multiclasses Ulfen Guard, Viking Fighter, and Barbarian would have three different pools off Rage to draw on, not one big pool of all his possible rounds.
Rage (Ex): An Ulfen Guard is trained to harness her brutish nature while in combat in the defense of her charge. This works as the barbarian ability of the same name. An Ulfen Guard’s class levels stack with any other classes granting this ability for determining the effects of rage powers and the number of rounds per day the guard can rage.
|Earl of the Malebolge|
No, because you would gain rounds of rage/day from ulfen guard, using your Ex-Barbarian levels with it, since barbarian as a class grants rage. (pretty sure that;s how its stated with Ulfen Guard NPC from one adventure or another)...
If that's not the case, as I GM I would houserule it so, because it makes more sense for a loyal Ulfen Guard to be lawful in nature then chaotic.