"enworld" has been taken, but it looks like enworldorg is available, etc.
As far as I know, you can't change your name (effectively keeping all followers).
I would grab a new twitter account with a name such as enworldorg (or whatever is there that you would prefer). I would then start posting updates under THAT name (TweetDeck helps you easily manage multiple twitter accounts) and then Re-tweet those with your current Morrus account - people will add the new account pretty quickly, especially with some daily suggestions to do so from the Morrus account, etc.