I was thinking the same thing too. Perhaps, Dayal might have some past with Goenka's. Or, maybe, the Goenka's might have done something to hurt Dayal by causing pain to one of his loved ones. I was thinking, that perhaps Dayal actually has a daughter named Durga. Before Nitya came, I think Dayal actually had a daughter named Durga, but perhaps she deceased tragically in an accident or something. Maybe thats the reason why Dayal adopted Nitya and gave the identity of Durga, his daughter to her. But I do hope that Dayal in honestly a good and noble man. Hopefully, he retaliates for Durga. Also, I hope he does not deceive her in any way. But there is definitely something suspicious about Dayal, I think so. Maybe he has a past which is why he is helping Nitya/ Durga...?