Applied through my school's Handshake for the Consultant intern position for undergrads.
First round interview was 45-min, and was essentially a case interview with a few mins of questions and "tell me about yourself" mixed in.
I was told I passed the first-round interview about 4-5 days later, and schedule a second-round interview a few weeks later.
The second-round consisted of 3 case interviews and 1 lunch (semi-behavioral) interview. Each interview was with a different interviewer. Each of the case interviews also had different behavioral questions mixed in. The cases usually focused on Revenue-growth and pricing and rarely touched costs.
The lunch interview was a relaxed interview with some behavioral components mixed in.