Revelation of a short ballad penned by formidable storyteller (10)
I believe the answer is:
apocalypse
'revelation' is the definition.
(synonyms)
'a short ballad penned by formidable storyteller' is the wordplay.
'short' means to remove the last letter.
'ballad' becomes 'calypso' (I've seen this before).
'penned by' is an insertion indicator (inserted letters are penned in).
'formidable storyteller' becomes 'poe' (I can't justify this - if you can you should give a lot more credence to this answer).
'calypso' with its last letter taken away is 'calyps'.
'calyps' put inside 'poe' is 'pocalypse'.
'a'+'pocalypse'='APOCALYPSE'
'of' is the link.
Can you help me to learn more?
(Other definitions for apocalypse that I've seen before include "Catastrophic event" , "the last item" , "End of the world" , "prophetic disclosure" , "Violent event" .)