>>23200790
I've always taken their last fight as Treize realizing he was basically doing the same thing to Wufei as he was to Lady Une. His mere presence in the world was driving Wufei crazy with a desire for revenge. Rather than see another "friend" shed their nobility like Zechs was doing with the whitefang shit. He instead just on the fly choses to deny Wufei his satisfaction and close that door forever before Wufei could go down that path. Of course Wufei being a moody dipshit doesn't actually smarten up until basically the same thing happens with Heero in EW.