Bill, the Dickens of a villain! (5)

I believe the answer is:

sikes

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'villain' is the definition.
(I have seen 'Dickensian villain' mean 'sikes' so perhaps 'villain' could also mean 'sikes')

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for sikes that I've seen before include "Dickensian villain" , "Bill - - in 'Oliver Twist'" , "Bill, the villain" .)

I've seen this clue in the Evening Standard.

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