The correct spelling of the phrase "more ballbuster" is /mɔːr ˈbɔːlˌbʌstər/ . The first syllable "more" is pronounced as /mɔːr/ with an open "o" sound, while "ballbuster" is pronounced as /ˈbɔːlˌbʌstər/ with a stressed second syllable and a short "a" sound. The term "ballbuster" is colloquially used to refer to someone who is demanding or strict, especially in a work setting, and "more ballbuster" implies an even greater level of strictness.