He painted Mona, and maybe Noel and Dora (8)
I believe the answer is:
leonardo
'he painted mona' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'maybe noel and dora' is the wordplay.
'maybe' indicates anagramming the letters.
'and' is a charade indicator (letters next to each other).
'noel' put after 'dora' is 'doranoel'.
'doranoel' with letters rearranged gives 'LEONARDO'.
'and' is the link.
Can you help me to learn more?
(Other definitions for leonardo that I've seen before include "and 12 Across: Renaissance genius" , "The Mona Lisa was painted by . . . . . . . . da Vinci" , "Da Vinci's name" , "Da Vinci and DiCaprio" , "-- di Caprio, actor" .)