William's expression became incredibly cold after he had received confirmation that it was indeed his cousin, Eve, that was about to be crowned the High Priestess of the Demon Realm.
He was very tempted to barge into the capital city of the Demon Realm, Astryae, to rescue her. But, he knew that if he did that, he would just be doing Ahriman a favor by allowing himself to be captured.
William had locked himself up inside his room, and no one dared to disturb him. They were afraid that if they tried to talk to him in his current state, he might accidentally lash out at them, and this was something that neither side wanted to happen.
When the Half-Elf asked the spy that was stationed in the Demon Capital if they saw a veiled woman accompanying his cousin, they only shook their heads and reported that no such woman was seen alongside the soon to be High Priestess.