Sit with a revolutionary storyteller (5)
I believe the answer is:
aesop
'storyteller' is the definition.
(Aesop is an example)
'sit with a revolutionary' is the wordplay.
'sit' becomes 'pose' ('pose' can be a synonym of 'sit').
'with' says to put letters next to each other.
'revolutionary' is a reversal indicator.
'pose'+'a'='posea'
'posea' backwards is 'AESOP'.
(Other definitions for aesop that I've seen before include "Poses as ancient Greek writer" , "his writings were fabulous" , "Greek fabulist (Tortoise and the Hare)" , "fabulous figure?" , "Greek author of fables (c 620-560 BC)" .)