For a moment there, William couldn't think about a reason for all this but thanks to the actions of the Aspire academy back there.
It was clear to him that the actions of the spirit masters of the Aspire academy were taken quite seriously by the dark spirit master community. "I won't be surprised if this was the root for all this," he thought to himself.
He never thought it was all thanks to him. It was partially related to the actions of the Aspire academy indeed. But the dark spirit masters decided to make an example of him and his team for others, so no one would follow suit of the Aspire academy's hostile and aggressive actions.
It was like a deterrent action, by taking him and his team out, others would get scared from following the Aspire academy's example.
William knew the moment he'd arrive at the main fort of the Scorching Lands; he'd part ways with this group of spirit masters. The more they talked and expressed their ideals, the more he despised them.