Risk Advisory is all about helping our clients solve problems. Maybe your customer came in not knowing they had a problem and you were able to identify that problem and solve it for them. This is a critical skill to demonstrate in an interview. Think of an example that fits your experiences and highlight your skills with an example (remember identify the problem AND the solution).
A few minor qualities or experiences to highlight include your ability to work in a professional environment, communicate with people of all different backgrounds, work in teams, leadership positions, problem solve, attention to detail, etc. Again, demonstrate this skills through past experiences. Maybe through volunteer work?
A final thought to keep in mind, -- the Risk Advisory practice is not exclusive to accounting or information systems majors. If you have an alternate educational history, show to your interviewer how you will be able to help the team because of that degree in ways that the typical majors might not be able to. This practice is wide open to all types of applicants that can help view and solve problems through different mindsets. With that in mind, there will be a case study interview. Try to brush up on a few accounting/information system terms.
For an intern position, key qualities that EY looks for is a friendly personality and an eagerness to learn. It can be difficult for an interviewer to determine how you are as a person so that is why it is key to answer their questions in a personalized and friendly manner. Be sure to support your resume with stories/experiences. For instance, they can ask you a simple question but you will have to respond with examples in your life pertaining to their question. Don't just simply reply with a short answer. Your responses to their questions is what will set you apart from the other candidates.
During an interview for Risk Advisory I would highlight any experiences you had with content learned in Accounting Information Systems as a lot of the work done in Risk Advisory coincides with the content that is taught in the class. In addition, I would highlight any time you have been in a professional setting or had done any audit work. Finally, be sure to highlight a willingness to learn and ability to be a self starter, problem solver.