At VOtE, Sasuke develops third tomoe just as he puts on headband to fight. According to manga, that is from pain of loss: i.e. cutting ties with Naruto. The friendship seems forced because Sasuke only shows the angry/dark side of any emotions.
kishi made it so everyone who crosses paths with Nardo and Sasky licks the ground they walk on with nardo its more understandable since he is a larger than life hero and saves everyone but Sasky is a criminal yet everything he has done is out the window cuz hey its Sasky he cant be in trouble and has kage he JUST MET willing to give up there souls for him! what a shit