Why Kabir wants this?

Kabir said to his partner that it's very much important that Ridhima "Thinks" Vansh as a criminal. Just note it, he wants that "Ridhima have to believe that Vansh is a criminal", nothing else. I mean, why it's important to Kabir ?

There has to be a past connection, where Ridhima is involved. He has a partner in that house, why would he need anyone else?

What if, it's Riddhima who is Kabir and everyone's target from day -1?

There is more to it, I am sure.