Available Cosmetics
The available cosmetics in game are currently the Costume Appearance, Wing Appearance, and the Weapon Appearance.
Costume Appearance
All transcendence costumes have a 'natural' appearance. Upon sewing of the costume, they have a 'starting' design. To change this design to another design, talk to the NPC Viola. Every appearance change requires some amount of Mystical Fabric and a small amount of dils.
Wing Appearance
Similar to transcendence costumes, wings have a 'natural' appearance. Upon opening of the wing box, they have a 'starting' design. To change this design to another design, talk to the NPC Viola. Every appearance change requires some amount of Mystical Feather and a small amount of dils.
Weapon Appearance
Weapons, on the other hand, are different. They do not have a costume on their base versions. To change appearances, it requires a weapon cosmetic item. Here is an example item:
To change the appearance, talk to NPC Ian in Ardeca and just choose the weapon you want to change appearance, and select the weapon cosmetic.