Bing Lieu, or Alastar Lupin, as his real name was, brought a lot of trouble to Takuan and his companions.
The sorcerer dedicated his entire life to the pursuit of power. His diligence and talent attracted the attention of the Dark Lord himself, who appeared before the sorcerer and entrusted him with a mission to travel to Chinayindu and acquire magical items. In return, the Dark Lord promised Alastar Lupin power that could only be matched by the celestial beings.
If you want to know a little more about Bing Lieu, you must visit his page on Makipedia.