I think today's vihaan parts were just to confuse us, vansh is the main character in this show and this show is all about him. In just 100 episodes his character can't end that easily.
We will exactly get to know whether he is a doppelganger or vansh himself once he meets Riddhima.
I do miss vansh but I did enjoy vihaan too today😆 My gut feelings say this guy is vanshi only, i feel he must've planned all this to give riddhu a taste of her own medicine.
I can imagine Ridhz getting sick of him snooping around the mansion once he re enters to 'impersonate' Vansh🤣