Soul Beasts

Number One didn't know as much about Soul Beasts as he did about Alchemy but those two fields were more tied together than people thought. He knew about one Soul Liquid that had a history with the Emerald Viper and it happened to be one of the main ingredients for many Heaven ranked pills. 

Number One waited until Darius was done explaining their mission to the other students and finally questioned, "Is the Emerald Viper perhaps hiding in the cave?" 

His question didn't calm the other top class students who were clearly panicking after hearing who they were going to face. Even if they just planned on watching from afar, it was still dangerous and many would try to avoid going if they knew beforehand. 

Too bad, they have already boarded the flying ship and could no longer debark.