Congrats on the 2nd round - almost there :-)
The first thing that you should know is that you have what it takes and you can go confidently into the 2nd round. The 2nd round is just to confirm what has been noticed during the 1st, yet with a different set of eyes from more senior firm leaders.
Now to your questions:
The final round should be like the first round. You will be evaluated on the same criteria, and metrics, with the same types of cases and questions.
Now, that's the theory. :-)
Quick reality check!
That being said, partners still often employ their own way of doing interviews based on their personal preferences, which means that sometimes the final round with them can be less predictable.
Some focus on the case, others focus solely on the fit part, and some stick to the standard format. I had a candidate recently who had to go through two cases and one of them was made up on the spot, which made it very tricky.
In general, the more senior the partner, the more likely are they to deviate from the standard interview format because they a. can b. have their own way of doing things. :-)
So now you know the practice.
What does this mean for you and your preparation?
Continue with your preparation, meaning
- Rehearse and finetune your fit answers with a coach or peers who know what they are talking about
- Hone your case interview skills that are relevant (structuring, math, exhibit interpretation) with coaches and drills
- Pay special attention to the areas where you received negative feedback in the first round. Second-round interviewers are aware and will dig deeper into these specific areas
During the interview
- Stay cognitively flexible
- Do not be surprised if the format deviates from what you expect
- Stay calm and collected no matter what happens
- Stay enthusiastic, and engaged, and portray the impression that you are happy to be here (partners love that...)
If you managed to pass the first round, you should have it in you to pass the second round as well.