No, you don't have to create any special account to play <Rise and Rule>. You can log into the game by using Apple Game Center (for iOS) or Google Play (for Android).
This way, you can also access your account from various Apple or Android devices, meaning you don't need to worry about losing your progress.
However, you will be playing in guest mode if you didn't enable your Game Center/Google Play account, or didn't use them at the beginning of the gameplay.
Rest assured, your account is bound with your current device. You won't be experiencing any account issues as long as you play on the same device. Still, it is highly recommended to bind your Apple Game Center (for iOS) or Google Play (for Android) account in game settings to avoid any possible issues.