Reportedly succeeded me formally (3)
I believe the answer is:
one
'me formally' is the definition.
('one' can formally mean 'me')
'reportedly succeeded' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'succeeded' becomes 'won' (I've seen this before).
'won' sounds like 'ONE'.
(Other definitions for one that I've seen before include "Ace" , "time" , "Half of two" , "Single person or thing" , "Single, sole" .)