This card had an errat in RRG 1.7, to specify who should resolve the ability.
It should read:
When Defeated: The defeating player searches the encounter deck and discard pile for a copy of the Misled treachery and shuffles it into their deck.
When Defeated: Search the encounter deck and discard pile for a copy of the Misled treachery and shuffle it into your deck.
This card had an errat in RRG 1.7, to specify who should resolve the ability.
It should read:
When Defeated: The defeating player searches the encounter deck and discard pile for a copy of the Misled treachery and shuffles it into their deck.