Performing with itself? (6)
I believe the answer is:
sprite
'performing' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
I don't understand how the rest of the clue works.
(Other definitions for sprite that I've seen before include "Dainty type" , "Brownie" , "Stripe on a fairy" , "Pet, sir, could be a goblin" , "A fairy or goblin" .)