One doing twist in flexible roles, nothing less (8)
I believe the answer is:
swindler
'one doing' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'twist in flexible roles nothing less' is the wordplay.
'twist' becomes 'wind' (synonyms).
'in' means one lot of letters goes inside another.
'flexible' is an anagram indicator (I've seen this in other clues).
'nothing' becomes 'O' (O resembles 0).
'less' indicates named letters should be taken away (less can mean minus).
'roles' with 'o' taken out is 'rles'.
'rles' is an anagram of 'sler'.
'wind' going within 'sler' is 'SWINDLER'.
Can you help me to learn more?
(Other definitions for swindler that I've seen before include "Trickster" , "Crook" , "Con man" , "Con artist" , "Fraudulent person or cheat" .)