More than a skill, a weapon.

'When you used this golden aura,' Uruk explained, 'I sensed the darkness covering my soul recede. Your aura chased away the madness that corrupts my soul.'

'How can this be possible?' Aito mentally, 'Aura of Bravery isn't supposed to work like that.'

[Yes it is,] Valinar joined the conversation, [Aura of Bravery is more than just a mere skill, Aito. It's the exact opposite of the Fear. It's a weapon that's been wielded by bravers to kill fearmongers. Those filthy creatures fear it. Didn't you see how they reacted? Each time you fought a fearmonger, they lost their composure. Partly because they think themselves invincible by using the Fear.]

Now that Valinar said that, Aito thought back on his two occasional encounters with fearmongers. Both of them had feared him greatly. However, that did not explain why the berserkers had reacted this way and why Uruk was awake.