This scene is when Sai was dreaming the same dream over and over
Sai: you again...
other Sai: So, we meet again my other-half
Sai: why... why do keep coming back!!
other Sai: Well isn't it obvious? I want you to accept me
Sai: No... no you killed my comrades!!
Other sai: Don't you mean "we" *grinning*
Other Sai: HaHAha, Come on face the facts, your far too weak to protect anyone, let alone yourself, but if I'm in control you won't have to suffer, so what do you say?