There are advantages to creating your own character. If you find one that you like and that you can write RPs for then you can use him in more than one E-Fed. Once you have established your wrestler in more than one E-Fed then you have started on your wrestler's career. Some wrestlers go through a dozen promotions and carry many titles. Others get tired of using the same wrestlers and change up in every promotion. It's up to you which you choose.
Eventually, you will want to retire your wrestler after they have acheived what you wanted them to do(or failed, it happens). Some handlers build web pages dedicated to their wrestlers and some just forget them and move on. Like I said before, it's up to you.