One is absorbed by Rocky sequel - instant classic (14)
I believe the answer is:
quintessential
'classic' is the definition.
(thesaurus)
'one is absorbed by rocky sequel instant' is the subsidiary indication.
'one' becomes 'i' (roman numeral).
'is absorbed by' indicates putting letters inside.
'rocky' indicates anagramming the letters.
'sequel'+'instant'='sequelinstant'
'sequelinstant' anagrammed gives 'quintessental'.
'i' inserted within 'quintessental' is 'quintessential'.
(Other definitions for quintessential that I've seen before include "Most crucial" , "Most perfectly typical" , "Representing the most typical example" , "flexible" , "Perfect; most typically representative" .)