Novel style of energy weapon — disintegrating ray (10)
I believe the answer is:
epistolary
'novel style' is the definition.
(an epistolary novel is a novel written in letters)
'energy weapon disintegrating ray' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mci).
'weapon' becomes 'pistol' (pistol is a kind of weapon).
'disintegrating' indicates an anagram (I've seen 'disintegrated' mean this).
'ray' anagrammed gives 'ary'.
'e'+'pistol'+'ary'='EPISTOLARY'
'of' acts as a link.
(Other definitions for epistolary that I've seen before include "Church book" , "Dealing with letters" .)