Tang Ziyi knew the Void Thunder Manual and might have some connection to the Thunder Emperor.
The Thunder Emperor had been suppressed for hundreds of thousands of years. Tang Ziyi was young and naturally could not be the Thunder Emperor's successor. However, she could be the disciple of the Thunder Emperor's successor.
It was because of this relationship that Su Zimo could not watch Tang Ziyi be trapped to death by the otherworldly soldiers.
Tang Ziyi was extremely smart as well.
After fighting against the otherworldly soldiers for a while, she felt that something was amiss. Just as she was hesitating whether to advance or retreat, Su Zimo's voice sounded.
Without hesitation, she leaped into midair and sped forward.
As an assassin, she had always been alone and had no friends since she was young.
Her parents died early and she trusted no one other than her master.