To me the leadership characteristic I look for is someone who is inspiring.
In my final nursing school placement years ago I had one main preceptor, and one part-time preceptor. My main preceptor was very much a manager: cold, by-the-book, minimal personality, effective and efficient, and knew the facts about everything. I learned a lot from this preceptor, but really only about the job in the LTC where I had my placement.
My part-time preceptor was the one I would say was the true leader. She made me feel welcome to the profession, but was honest about the challenges that came with the title and career. She was very book smart as well and knew a lot about how the organization was run, but she was very personable too. She generally cared about staff and patients and never forgot anything that someone told her. She always wanted to know what people were up to and how they were feeling.
I feel balance of intelligence and humanity makes a true leader. This woman made an incredible nursing leader who still inspires me to this day.