Only One Can See

Don't worry, you're only ｓｅｅｉｎｇ ｔｈｉｎｇｓ.

When only one person can see things that are real. If they're seeing these things and they aren't real, then the things are hallucinations. This can be because this person is the Chosen One and it's part of their destiny to be the only one who can see or they have a Unique Ability that allows them to see. It's also possible that both are true.