From what Alex realized, the poison's main purpose was one of two things.
It either entered one's Dantian to destroy the Nascent Soul, or it simply sought out the Nascent Soul around the body to destroy it. However it did it, it went after the Nascent soul and destroyed it.
Alex could feel his Soul dying to the presence of the poison and instinctively forced his body to protect itself. The Yang in his body surged the moment they were allowed again and the poison was immediately burned up.
Alex was left breathless. He took in deep breaths, calming the feeling of momentary dread he had felt.
That was a very dangerous poison. To him it was fine, but to anyone else, their death would be instant.
"Level 10… It might just be," he thought.
Hannah had gotten herself in rather dangerous trouble.
Morning came just a few hours later, and Alex relayed what happened the last night to his two elders.