[Fufu]

To go from Level 9 to Level 10 (win condition), a player must kill a Monster, unless the card says otherwise. Kill means total strength/power of the player(s) in Combat, and defeat means anything other than a player(s) combine strength/power basically.

If the card had stated, "automatically killed by Cedric Diggory" then yes, you would go to Level 10 (win). However, defeat means you cannot gain the winning Level.