The Mirror bosses are a set of boss monsters in Dragon Quest Swords which are available only after completing the main story plot by defeating Xiphos the Deathbringer. The term 'Mirror bosses' was created by fans in order to refer to this set of boss monsters specifically. The name derives from the fact that each of the bosses are accessed via a mirror in Olde Reflectory. Defeating all of the mirror bosses unlocks Payback Mode.