To unlock disguises, complete the "Spider Nest Castle" main mission (Kinki region). Then, enter the hidden teahouse from the starting point on the map (where you also access the blacksmith). Select "Trade", then "Transform". Choose a disguise you want to purchase, then select "Transform" in the hidden teahouse. This will overwrite your current outfit. Gear you equip will not alter the look of the disguise. Use a disguise to get the "Disguiser" trophy. You need a minimum of 1,300 glory for the cheapest disguise (Hattori Hanzo). You get glory from fighting revenants (the red graves in missions that spawn the ghosts of dead players). You can farm it quickly by replaying low level missions where a lot of players have died.