Generally while sitting for a Management Consulting Interview a plethora of skills are being tested in a person these tests are generally concentrated towards the analytics and communication skills of a person. The main reason behind this is that generally the whole work of a Management consultant revolve around these two domains. The way you analyze the situation they way tab present your point of views creates a huge impact on the clients mind.
But let us get deeper into this and understand all these things in a holistic manner
Let's talk about the interview process for the big three Management Consulting firms on thsi planet which generally includes Boston Consulting group, McKinsey& Company what are the procedure been undertaken by them they generally conduct a group discussion for the candidates, afterwards they conduct one of the compulsory rounds in the interview process that is the case study round
Generally what happens in a case study round is that you would be given one particular industry take for example Hospitality industry and then the current and that future prospects would be given for that particular industry then you would be given one company wants to penetrate in the market and you would have to provide advisory services regarding the same
The final round of the interview process is personal interview where the companies generally check your soft skills which includes communication skills and decision making skills and most importantly your leadership because how intelligent you may be what matters the most is your leadership skills how would you manage a situation and how would you tackle all the hurdles coming in your pathway

Hope this article would help you somewhere
And would surely help you in an MBB interview

References
Case interview.com, Quora, Prep Lounge.com
The image is been created by the author on Canva