Massive fan of sci-fi endorsing Banks (5)
I believe the answer is:
fiend
'massive fan' is the definition.
'fiend' can be an answer for 'fan' (thesaurus). I am not sure about the 'massive' bit.
'sci-fi endorsing banks' is the wordplay.
I cannot really see how this works, but
'fi' is within the answer.
The remaining letters 'end' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Other definitions for fiend that I've seen before include "Devilish person" , "Evil supernatural being" , "Operatic super-soprano" , "Demon, ogre" , "monster" .)