Sahir hates himself. So much so that he loses himself in a shark like character who is remorseless, cunning and unforgiving. Totally opposite to him. He has mentioned a few times about how he has nurtured his pain. He certainly has, and created a monster. This creature protects the vulnerable Sahir hidden in the depths of his heart. He actually blames himself for the Zeenat betrayal. If he had been the shark, this would never have happened. No one would have even tried to betray him. The weakness was in him for being so vulnerable, naive and trusting. Him proving a point to Zeenat is actually proving a point to himself. He has totally killed the old Sahir so no one will be able to get close enough to hurt him ever again.
But the pain he has nurtured has become like a spoilt child. Sahir over indulged it, gave it more importance than needed and now it controls him. He has become a slave to it, like a drug addict, who knows he needs to overcome this addiction, but that is easier said than done. The mind is so powerful, it can force the strongest hearts to kneel before it. And Sahir is no exception. The same way, drinking alcohol in moderation prevents addiction, but as soon as you start using it as a comforter, you lose control and it controls you. This is exactly what has happened to Sahir.
Then Arzoo enters the picture. He sees the old Sahir in her and loves her for it. But his nurtured pain isn't going to let him change. He isn't allowed happiness, because that will lead to suffering. So he pushes back, asks her to stay away. But her aura is too strong, it's calling out to the old Sahir and that Sahir, slowly but surely is pushing to return. But then Rehman, Zaki, pregnancy all happens. We see a vulnerable Sahir. Overwhelmed with anguish. 'See Sahir, I told you the world can't be trusted' says his nurtured pain. And there you were, going back to your old self. You really are a fool. And so the nurtured pain gets the upper hand again. He needs to be the shark. He needs to put that old Sahir back where he belongs. Locked up and forgotten.
And so begin the shark games, but His nurtured pain, so self absorbed and drunk with victory fails to hear the faint but strong hammering away of the old Sahir, he isn't going to give up that easily. Aarzoo's love is calling him and he'll be damned if he lets her go.