It was indeed Feng Saohuang who led the group of soldiers to detain Mubai. He was responsible for overseeing Munan's case so it naturally fell on his shoulders to detain Mubai. It was also because it was him who headed Munan's case that the Xi family had trouble clearing Munan's name.
The Xi family didn't dare to pull some behind-the-scene strings because this was a sensitive time, one wrong step and they would show a weakness for their enemy to exploit. This was why Grandfather Xi had gone looking for Lin family's help.
The Lin family had great influence around the capital. Furthermore, they had easy access to the national intelligence agency.
In the end, to their consternation, they formed a new enemy in Lin Yun whom Grandfather Xi had expended a great deal of effort to invite over. And now, Feng Saohuang had led his troop over to capture Mubai!
Things couldn't get any worse for the Xi family.