Dramatic summoning by old flame (8)
I believe the answer is:
exciting
'dramatic' is the definition.
(I've seen this before)
'summoning by old flame' is the wordplay.
'summoning' becomes 'citing' ('cite' can be a synonym of 'summon').
'by' means one lot of letters go next to another.
'old flame' becomes 'ex' (I've seen this in other clues).
'citing' put after 'ex' is 'EXCITING'.
(Other definitions for exciting that I've seen before include "Arousing thrill or expectation" , "Causing much enthusiasm" , "Exhilarating, stirring" , "stirring things up!" , "Stimulating, stirring" .)