mightiswright | ♠ permissions

In canon, Phoenix has an object called a magatama which lets him see when someone is lying. Because it requires someone with spirit power to recharge it all the time, I've converted it into an actual superpower for him.

Ability to tell when someone is lying... via being able to see a giant lock slam over his view of them. I'm basically adapting his canonical ability to see when someone is hiding something and expose it, via a spiritually charged stone, into an actual innate power. The more severe/complicated the lie, the more locks there'll be. If he can get the person to speak some degree of truth about the topic, then the amount locks will shatter accordingly to let him know they're starting to open up. This is not confined only to someone who is speaking to him, but only if he can hear them.

Of course, just because he sees it doesn't mean he necessarily has to point it out. So feel free to comment here if you'd prefer for him to not bring it up, or if you think your character has reason why it won't work on them!