So we see in KH3D that Saix was taken by Xenahort and became one of 13 Xenahorts. But, playing again Kingdom Hearts 358/2 Days, it's quite obvious that Saix didn't know about actual plan of Xenahort (in fact he asks Axel to search the chamber of sleep) and he didn't have a reason to join him...so why now is he taken down by Xenahort? It's strange, he is a smart person, maybe he is really a spy or something.
So we see in KH3D that Saix was taken by Xenahort and became one of 13 Xenahorts. But, playing again Kingdom Hearts 358/2 Days, it's quite obvious that Saix didn't know about actual plan of Xenahort (in fact he asks Axel to search the chamber of sleep) and he didn't have a reason to join him...so why now is he taken down by Xenahort? It's strange, he is a smart person, maybe he is really a spy or something.