What does khatri want????

Its really odd that since 7 years khatri is stalking dixits and there house, knows what is happening with them and no one knows about it. Possibly not even ishwari. Yesterday sona offered lot of money to khatri but he didn't even think about taking it. But we have seen him blackmailing ishu for money in the beginning. So what does khatri ultimately wants????? So much dedication in stalking dixits and keeping ishu's secret!!!! So what's his end game!???