Crossword Genius

One in a rush to claim riches involved demon girl (4,5)

Ross

I believe the answer is:

'one in a rush to claim riches' is the definition.
(person who mines for riches)

'involved demon girl' is the wordplay.
'involved' is an anagram indicator (involved can mean confusing or complex).
'demon'+'girl'='demongirl'
'demongirl' anagrammed gives 'GOLD MINER'.

(Another definition for gold miner that I've seen is "fortune hunter".)

I've seen this clue in The Guardian.