Original sentence: Sukuna proved to be an exceptionally able student; author Deryck Scarr later said of him that he spoke English with "the bell-like tones of standard southern English, as though he had studied diction with the royal family" - a compliment rarely paid even to a native speaker, let alone one who knew English only as a second language
Edited sentence: Sukuna proved to be an exceptionally able student; it was later said of him by no less an authority than Deryck Scarr that Ratu Sukuna spoke English with "the bell-like tones of standard southern English, as though he had studied diction with the royal family" - a compliment rarely paid even to a native speaker, let alone one who knew English only as a second language