Astaroth was still processing what Aravelle had told him and taking a moment to decide if it was a truth he would accept. After all, even if he had finally integrated with the rest of the fragment of divinity inside him, he was far from feeling godly.
At best, he felt stronger than before. At worst, he felt it had taken something he couldn't take back from him.
His humanity.
Astaroth could tell he had deviated from that which bound him to the human race for a while. But he thought that wouldn't be for long, given the rest of humanity was also changing.
However, now that he had consumed that fragment, he could feel the souls of the people around him when focusing, and he could tell that wasn't something just anyone could do. And it scared him.