Alchemy is one of the menus you can access in the Setup Menu to enhance weapons and create gems. There are 2 submenus in Alchemy; Weapon Enhancement and Refine
Increases the quality of weapons. Gems are required to enhance weapons, and their requirements differ in number and element according to the weapon. An enhanced weapon will be shown as “weapon name +X”, where each +1 increases the attack power of the weapon by 5%. Sometimes, weapon enhancement can fail.
Here, non-weapon items can be broken down into gems. You can preview the number and type of gems that an item can be broken down into by pressing SELECT button.