In Clair Obscur: Expedition 33, your main method for customizing your character builds is the use of Pictos you find everywhere throughout the world. Pictos are kind of like Materia in Final Fantasy 7, or Guardian Forces in Final Fantasy 8: you equip them to your characters to grant them a variety of passive benefits, always including one or two stat boosts and a special condition. Once you've had them equipped for four winning battles, all your characters learn them permanently as Luminas, and can use their special conditions without having the Pictos equipped.