As with much of Xiao Fa's past, Shanxi's history with him is unclear. The party has the impression that Shanxi and Xiao Fa were partners in crime.
Shanxi has his own small band of thugs. He wants his brother back. He claims to see Xiao Fa as an imposter in his brother's body.
The party convinced Reiko not to kill Shanxi when he entered the service of the Shadow.
Shanxi is extremely cautious. He is unlikely to start a fight, unless he finds the one who "murdered" his brother.
His core beliefs include:
1. Power and respect are a measure of success. (now at -1?) 2. Money garners power and respect. 3. He who robs me is my enemy. (now at -1) 4. Protect your people against the world, and they will protect you. 5. To be safe, never let an enemy choose the terms of the conflict. 6. Keep your bargains
For Xiao Fa
This part Yoshi only volunteers to Xiao Fa.
Since Xiao Fa told Yoshi that he is reasonably sure that he choose to lose his memories, Yoshi operated under that belief when speaking with Shanxi. Shanxi was outwardly unmoved, saying "Nobody gets to tell me it was right and proper to destroy my brother's mind because he was unhappy. Not even him." But Shanxi is inwardly more conflicted than that. I believe he understands more than he will admit, perhaps even to himself.
His wish to "get his brother back" stems primarily from his resentment at being "robbed," and his belief that he failed to protect Xiao Fa. When I learned this, I told him that you had three times rejected the master of his new employers, and that that master would now seek to kill you. I am confident that he will not use this information to harm you, and there is a chance he will act to help.