I think you can overcomplicate this question but a leader is someone that, over time, people follow. Why they follow is up to the individual. Gandhi was a lead

I think you can overcomplicate this question but a leader is someone that, over time, people follow. Why they follow is up to the individual. Gandhi was a leader, but then conversely, Hitler was also a leader. There is no morality in leadership, but I would say a common trait would be charisma.