Eg WG Grace period reflected the spirit of the Ashes? (5)
I believe the answer is:
dryad
'spirit of the ashes?' is the definition.
(wood spirit in Greek myth - ash is a type of tree)
'eg wg grace period reflected' is the wordplay.
'eg wg grace' becomes 'Dr' (cricketer WG Grace was nicknamed the Doctor).
'period' becomes 'day' (day is a kind of period).
'reflected' shows that the letters should be reversed in order (letters reflected back).
'day' backwards is 'yad'.
'dr'+'yad'='DRYAD'
'the' is the link.
(Other definitions for dryad that I've seen before include "Tree nymph" , "Nymph of trees" , "Mythological wood nymph" , "Wood-nymph" , "Spirit in the wood" .)