Board Thread:Theories and Speculation/@comment-37697942-20190205112640/@comment-31099706-20190205143149

That would be a good twist. Since Kashin and Sasuke never been in one place together. But still, I feel Kashin seems to have relations with Kara and Ao longer than Sasuke became good, or maybe he Kashin joined Kara about that time or Sasuke just genjutsud them or something like that.

I have no idea why he would do so though, he could easily gather info from a genjutsu, so there is no point in causing harm. And we do know that Kashin had his inner monolouge where he remembers Konoha and stuff. So, unless the Uchiha take their secret undercover/spy/fake identity that seriously, I would say no. Though I for one have a guess that Kashin probably is acting as a spy just like Itachi did.