Weapon Symbols (Idola)
By equipping the character with a symbol, it will be effective, and you will be able to receive benefits such as status up and ability effects. There are two types of symbols, "weapon symbols" and "soul symbols", and there are various ways to obtain them. There is also a "Symbol Fragment" that can be used to generate symbols by collecting a certain number or to strengthen the finished product.
List of Weapon Symbols