Orion
This is the approximate size of the circle around the character. The green dots are very faint, so I drew some red lines to make it clear how big it is. It’s similar to a self cast ‘silence’ aura circle, magic circle against alignment, or ‘battletide’ circle in size. I just made this in game with the Pretty Good Character Creator Module v3.
In Vanilla NWN, enemies can fail the roll from TR, not have fear immunity, and still fight back. TR has a paralysis effect in Vanilla rather than enemies running away in fear. Immunity to paralysis (from immunity to mind affecting, or freedom, or RDD 10, or PM 7) therefore prevents the paralysis effect from Terrifying Rage (TR). Therefore paralysis immunity in vanilla NWN counters TR, even though fear immunity causes a failed roll and a fear ‘visual’, there is no subsequent paralysis effect and therefore no practical effect (only a visual effect)
The NPC fighter in the screenshot I think is a good example. He failed the TR will save, but is still able to do things, funnily enough! I think he probably has a freedom item equipped. Pretty frustrating for my barbarian!
So in Vanilla NWN as you commented, a neutral aligned barbarian would have an advantage, by having a paralysis effect being able to bypass protection vs alignment. While an evil barbarian wouldn’t be able to affect enemies who have prot v evil.
In environments with modified terrifying rage mind immunity will not protect such enemies, nor immunity to paralysis from freedom/RDD/PM. WoG is one example of an environment where terrifying rage makes the enemy actually run away due to it being a true fear effect (similar to a Dragon’s Fear Aura, for example, except with a DC roll which is much much higher). In this environment, only fear immunity prevents the effect of enemies running away.