The first immortal account is the one that is specified in etc/server.cfg:
immortal_name = ~Papi~
You should change this to the name you will register on the MUD to be the Wizard of Wizards, the God of Gods. Once you've saved that and re-run the MUD, you will need to create the character by logging into the MUD. Upon the second login, you'll have the opportunity to set the wizarding level of the character. For ultimate power, you may set the level to 255. You may wish to set the Wizarding level lower on later logins to ensure you don't mistakenly fire off the nukes that you'll have with that maximum power.