Can't believe I'm the first one jumping on this! Okay, so 'Shehr-e-Zaat' – that book (and later the drama) honestly lives in my head rent-free. The absolute core is Falak, the protagonist. We meet her as this stunning, privileged girl who's utterly defined by her beauty and social status, which is her whole 'shehr' (city/world). Her arrogance and vanity are central to her initial role; she's the embodiment of worldly obsession.
Then there's the pivotal character of the Majnu figure, the Sufi beggar she mocks. He's not a traditional love interest; he's more of a spiritual catalyst. His curse (or blessing, depending how you see it) shatters her constructed identity. His role is to mirror her inner emptiness back at her.
Her family, especially her father, represent that comfortable, enabling worldly life she has to lose. And the real turning point comes with the introduction of Moin, the unassuming, pious man she eventually marries. He's less of a dramatic character and more the steady ground, the embodiment of a different value system – his role is to guide her towards humility and faith without any grand romantic gestures. The entire story is really about Falak's journey from being the 'key' character in her own shallow drama to becoming nothing, so she can become everything else.