Baffle Señor with regressive inclusion of reflexive pronoun (7)
I believe the answer is:
oneself
'reflexive pronoun' is the definition.
(I've seen this in another clue)
'baffle senor with regressive inclusion' is the wordplay.
'inclusion' indicates a hidden word.
'regressive' is a reversal indicator (to regress is to go backwards).
'fleseno' is hidden in the letters of 'baffle senor with'.
'fleseno' back-to-front is 'ONESELF'.
'of' is the link.
(Other definitions for oneself that I've seen before include "By this, unaided" , "Lose fen (anag)" , "normal" , "Being by this is alone" , "Reflexive pronoun" .)