MoQiu's family
Jiushu did some reading on Ruler's domain and on puppet belly.
The formation itself has no ways to break it.
Only, the ruler must give permission. Who's the ruler of a domain? The man with most power.
She can either starve the formation by cutting off all the power coming from ancestral lands, or she can create another ruler with more men than The emperor.
First places Xiao Xing in danger, later places herself in danger.
Jiushu went with Xiao Xing to just count the souls waiting to move on. It's impossible to finish them all within a few months.
Only, she has no idea how many subjects the ruler has, neither is she sure an alarm will not be raised when she converts his subjects into her own.
However, she is sure of onething. Between Xiao Xing and herself, she will always choose to brave the danger.
Thus, she stayed with Xiao Xing for morning rites of cleansing souls for two hours.