Being Different as a Speaker
Some speakers go the route of adopting the persona of a historical character. This has worked out very well for a number of professional speakers. One I know portrays Ben Franklin, another plays Albert Einstein and the list goes on from there.
If you feel passionate about a particular character from history, I wouldn’t dissuade you from going this route. Only do it if you have a great deal of passion for a particular person.
There are a number of other ways that you can choose to be different as a speaker. Some people wear odd shaped glasses or different color shoes. However, I would rather you make your mark as a great speaker, not as a clown.