The obvious answer would be Shyam but I actually think it might be Dadi's second son - Arnav's chacha (his father's younger brother). The same one who took everything away from Arnav and Anjali and threw them out of the house - the same one Arnav brought the house back from in the first episode. That chacha has all the connections to find out about another business man's dealings very easily and he might have poised Dadi's mind about Arnav and knows that the only way to punish Arnav would be through Khushi
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