What he says goes - on paper (8)
I believe the answer is:
dictator
'what he says' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'on paper' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'at' (I've seen this in other clues) and 'at' is present in the answer.
'paper' could be 'i' (the i is a UK newspaper) and 'i' is found in the answer.
This explanation may well be incorrect...
'goes' is the link.
Can you help me to learn more?
(Other definitions for dictator that I've seen before include "ruthless leader" , "One who reads out for others to scribe" , "One ordering" , "A domineering ruler like Stalin or Mussolini" , "Chaplin film showed a great one" .)