Annihilates confused man of letters from this Italian city (8)

'annihilates' is the definition.
The definition and answer can be both related to change as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?

'confused man of letters from this italian city' is the wordplay.
I cannot really see how this works, but
'man' could be 'n' (knight, a man in chess) and 'n' is present in the answer.
'letters' could be 'es' (more than one E) and 'es' is present in the leftover letters.
'city' could be 'la' (Los Angeles) and 'la' is found in the answer.
This explanation may well be incorrect...

Can you help me to learn more?