I noticed Owl seems to be sobbing in the cutscene before he lunges at Wolf in the battle atop Ashina Castle. Given what i know about Owls treatment of Wolf, this has me curious if he truly loved him as opposed to seeing him as a mere tool. Maybe im crazy, Maybe hes laughing? Or hes just old and grunty? Idunno. Sounds like crying to me.
He was definitely feigning sadness to make Sekiro lower his guard