The most common and most likely answer to this crossword clue is the 7 plus 2 plus 3 plus 5 letter word VILLAIN OF THE PIECE
I've seen this crossword clue in Independent
V
I
L
L
A
I
N
O
F
T
H
E
P
I
E
C
E
Buddy explains!
The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.