It's natural that Tiankui and the son of heaven attacked Qiankun sect.

emperor Qiankun collected all kinds of energy to strengthen himself. Tiankui wanted to block emperor Qiankun and reduce the danger behind him. He couldn't let emperor Qiankun continue to expand. At the same time, he also wanted to ensure the smooth implementation of his plan. Emperor Tianzi changed the script and accelerated the progress of the drama.

so, as soon as they got in touch with each other, they just agreed to work together to deal with heaven and earth!

of course, both of them didn't show up in person, but they sent their forces to come here....