You will be required to Register at least one RSI Citizen when creating your account; this will default as your Primary Citizen

Note the Validation check against the RSI Citizen Bio to verify ownership

You can register multiple RSI Citizen's to the same Crusader Cloud Account and switch the Primary being used at any time after Registering (Must be logged in)

Note the ability to Set Primary during Registration

Note the Validation check against the RSI Citizen Bio to verify ownership

After Registering an RSI Citizen you can change your Primary at any time on the Profile Page

Suggestion: Register all of your RSI Citizens to one account. Otherwise you will have to log out and log in to each Account whenever you want to switch