...wants to be noticed returning with captured duke (5)
I believe the answer is:
needs
'wants' is the definition.
('need' can be a synonym of 'want')
'noticed returning with captured duke' is the wordplay.
'noticed' becomes 'seen' (I've seen this before).
'returning' says the letters should be written backwards.
'with' indicates putting letters inside.
'captured duke' becomes 'd' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'seen' backwards is 'nees'.
'nees' placed around 'd' is 'NEEDS'.
'to be' is the link.
Can you help me to learn more?
(Other definitions for needs that I've seen before include "Demands" , "What is required" , "Essentials" , "Calls for" , "Can't do without" .)