The fact that Sovieshu could have always gotten what he wanted if he just remained active. He and Navier had such a beautiful relationship before, yet, the moment Navier changed for the country, he suddenly gets down on his luck.
For me, he's a narcissist that wanted someone with the innocence and nostalgia factor of his and Navier's childhood. He wanted someone to complete his wants for the perfect life.
When Rashta came and Navier changed, he saw Rashta as the embodiment of everything he wanted for the woman beside him. So him being a stupid-ass made Rashta stay beside him to act as a pseudo-Navier.
So now, everything's gonna go down hill. Now that Navier's leaving, Rashta will just become the empty vision he had of Navier. And he'll be someone who's perfect world will crumble.
If all he wanted was to see Navier smile, then he would've definitely been the perfect candidate to do so. Except, he left all the things they understood about each other and decided that waiting and acting wasn't gonna fill in his needs.