Right-hand man is Ariadne, oddly enough (4)
I believe the answer is:
aide
'right-hand man' is the definition.
(I've seen this in another clue)
'ariadne oddly enough' is the wordplay.
'oddly enough' means one should take alternating letters.
The alternate letters of 'ariadne' are 'AIDE'.
'is' acts as a link.
(Other definitions for aide that I've seen before include "auxiliary" , "Right-hand man/woman" , "Somebody helping" , "a help" , "Personal assistant in the military" .)