Beneath the clouds and sunlight, Gu Caiwei analyzed the Qi situation. There were three Huandan Doyens and the skilled Daoist Bai Suhuan; their Qi combined, in terms of combat power, was stronger than any ordinary school of cultivation. Compared to Qingjiang back then, they only had an upper hand in terms of crowd size. Furthermore, Bai Suhuan himself could match Huang Longzi from the Twelve True Zhenrens of Guangqing.
He gathered people of similar ideas to reason with them. It was a big world out there with tons of different approaches to Dao. Not everyone could be as charismatic as him, or if someone was not desperate, they would not have done it too.
Furthermore, the sky and Dao were interrelated. Xuanmen cultivators who observed to get a better understanding of things would understand that it was not illusory.