Location: Midway between the medial ends of the eyebrows Actions& Effects:
Calms the spirit - insomnia, anxiety, stress.
Sinus issues - congestion, sinusitis.
When Uncle is teaching Zuko about lightning, he talks about bending needing a certain amount of inner calm. So, if you were to close that chakra and lock all the anxiety inside someone, making them incapable of being calm, that would effectively take someone’s bending away.
Quite clever actually, since the more terrified they are/become the more permanent this block will be. And Amon is sure laying it on thick.