There are no "costumes" in this game, if by "costume" you mean cosmetic outfit to show off over your gear.
What the Armory system is, is simply an easy way to switch all your gear at once instead of one by one. You still show your actual equipment.
That being said, around lvl 15, you get a quest to unlock the Dye system, which can help improve the looks of your gear.
To be honest, it's kinda uncool that I have yet to see prettier gear than the starting clothes... aside from the endgame job armors.
What the Armory system is, is simply an easy way to switch all your gear at once instead of one by one. You still show your actual equipment.
That being said, around lvl 15, you get a quest to unlock the Dye system, which can help improve the looks of your gear.
To be honest, it's kinda uncool that I have yet to see prettier gear than the starting clothes... aside from the endgame job armors.
