Korn Ferry interview questions

I applied online through some networks of my colleagues. The whole process of Korn Ferry Hay Group was long and really tedious. And it really wasted candidates' time as well. First interview was with two Consulting Analysts with some simple questions like What was your biggest achievement? What was your strengths or weaknesses? Then I was processed to case interview. Case interview was not that hard as other traditional consulting firms. They just tested your structuring skills then asked some questions about why applying to Hay Group? Then I had to wait for the following 2 weeks for the next interview with Client Partner. Then they re-scheduled it again and again like 3 times. During the interview with Client Partner, I was asked some basic questions like What do you know about Hay Group? Why consulting? then the rest of the interview was asking about my personal life, which was something weird to me. He asked about something like What was your family background? What did you do during your free time? What was your favorite type of music? etc.. Then a day after, I was shocked that I got a rejection letter from them with not knowing why. My process took about 2 months. I sent my resume from July 3 and finished on the 3rd round on August 28. The experience was not comfortable at all.