Jiang Yunhai was indeed in the midst of a pursuit. The one who was pursuing him was the Divine Martial Kingdom's Royal Military.
When Shui Qianrou asked someone to pass the message to Zhangsun Wuji, he had to comply. Otherwise, this crazy lass would go make a huge commotion in the royal capital. He quickly thought of an idea and instigated the Third Prince, Xia Tian, to come to Spirit Beast City.