You set an illusion on a creature or an object you touch, causing the prophecy spell to reveal false information about the target. The target can be a voluntary creature or an object that is not clothed or carried by another creature.
Nystul’s Magic Aura 5e
Casting Time: 1 Action
Components: V, S, M
Duration: 24 hours
When you cast this spell, you choose one or both of the following effects. The effect persists for the duration of the spell. If you cast this spell on the same creature or object every day and choose the same effect each time for 30 days, the illusion persists until it is lifted.
An aura detection spell against a target and a magical effect (such as a spell detection spell) will display different information. You can make a nonmagical object display magic and a magical object display nonmagical; or you can change the object’s magical aura so that it displays the aura of a particular school of magic chosen by you. When you set this effect on an object, you can make this false magic appear to any creature that uses the item.
Detection spells and magical effects that target a creature’s class (such as a holy warrior’s “divine perception” or a spell emblem’s trigger condition) will display different information. If you choose a creature class, other spells and effects will assume that the target creature belongs to that class or to the camp to which it belongs.