After seeing Ancestor Wusheng, Wang Wei did not visit his family and returned to his Sacred Son Mountain to once again entered seclusion. He previously moved the Secret Realm with the Heaven Hiding Array inside.
Wang Wei wanted to calculate when Xu Shi would leave seclusion so he could go after her.
And the answer he received was that she would not leave the Academy until she entered the Saint Realm and showed herself to the world. And that was too late for him.
So, he calculated ways that he could lure her out of the Academy but failed no matter what tactics he used. The Academy seemed determined to keep her inside for as long as possible.
So, he deduced a future where he used his [Fate Stealing] technique to infiltrate the Academy and find Xu Shi's whereabouts. And as expected, something went wrong, and the Academy discovered him.