Alex wanted to interrogate, strike a deal, or whatever it took to gain the information he needed from Evangeline, but he knew he couldn't do so at the moment and could only watch her vanish before she even left his tent.
Alex knew that Ahrimon had something planned that would take out 80% of the inhabitants of the human continent, and the only real clue as to what could cause it was the Chaos Spawns.
But Alex knew that Ahrimon would know that it would be easy for him to find the movement of the Demonic cult, and if he was planning something with them, he would be more cautious.
So, for the time being, the only hope Alex had was the Human Emperor, who should be regaining consciousness in a few months because it was already close to the fourth month since his treatment began.