Intensity in shocking scenes with fire (10)
I believe the answer is:
fierceness
'intensity' is the definition.
(fierceness is a kind of intensity)
'shocking scenes with fire' is the wordplay.
'shocking' indicates anagramming the letters (I've seen this in other clues).
'with' says to put letters next to each other.
'scenes' after 'fire' is 'firescenes'.
'firescenes' is an anagram of 'FIERCENESS'.
'in' is the link.
(Other definitions for fierceness that I've seen before include "Ferocious quality" , "Violence" , "Passion" .)