Fashion Passion Achievement
Find and equip all Outfits.There are a total of 30 Outfits hidden throughout Chapters 1 through 14 that you must collect for this achievement. Note that, in addition to those 30, you will unlock five outfits automatically at the start of Chapter 14, and you will unlock another four outfits automatically after beating the game (Chapter 16). Those nine outfits also need to be equipped to unlock this achievement, meaning this achievement isn't obtainable until after you beat the game.
The following video shows the locations of all 30 outfits hidden around the chapters. NOTE that even though the choice you make in Chapter 3 significantly changes your path in Chapter 4, the outfits are present in both instances in Chapter 4, but in different locations obviously. They aren't missable nor do you need to replay Chapters 3 and 4 to obtain them. Just watch the section of the video for the path you chose.
After you complete the game and unlock your last outfits (assuming you followed the guide and your last outfits are the ones you unlocked after completing the game), reload any chapter through Chapter Select. Once loaded in, open up the Guardians menu, go to each Guardian's outfits with , and just scroll through every outfit and press on each to quickly equip them all. Once you've equipped them all, this achievement will unlock.
Video courtesy of MrWilliamThor: