yes, he does actually... well I'm not sure if he straight up said it but, yea. if you watch the 4th season it'll kind of explain why he's seen all his previous partners die. I hadn't even thought about it until reading your comment, just finished last season yesterday, only thing I can say is Saito definitely had to have been the most badass 'partner' Delf has had. but yes, he more than likely hinted that he's seen all his partners die