Be yourself and be calm but do a good amount of research on the company (it is good to show of your knowledge)
Don't even mention Reebok no matter how much you've had to drink at the lunchtime bonding session
Learn about the history of Nike and the Nike way of doing things.
Have knowledge on some Nike products and represent the brand at your interview. Avoid wearing other sports brands such as Adidas etc at the interview and this will be subconsciously noted by the interviewer.
Study some nike maxims/morals/beliefs
study a bit of history behind nike
Confidence, upbeat & enthusiastic.