I don't think hypnotism would have worked on Piya. Remember how PL failed to do that in college?
Yes, I remember that... But, then Pia also said that the jabakusum ka tel and sarso ke beej wala locket saved her... And then the makers didn't show anything like this.
But, yes it is quite possible that hypnotism wouldn't have worked on Pia.
Although we never know... As it is, the makers have shown Dev as way more powerful than Pia...
About Muh-Dikhayi or Dil's mom - honestly exhausted to even imagine. Jo dikhana hain dikhaye!
Dillu's mom... Well, honestly, I am not interested. But yes, I want to see Dev's partner's face... Baki makers ki marzi. Jo dikhana hai, dikhaye!!!