A Charmspeaker

Like a form of mind control, Charmspeaking can get people to do their bidding whether those people want to or not. So having the similar power of speaking things true, like charming the universe into one's will, being given to a Charmspeaker makes a lot of sense.

Charmspeaking is a gift for the children of Aphrodite, but can be taught to others who use magic. As well as being given to the children of Loki. It could be hinted Athena and Hermes could have that kind of power. Which might be given to their children as well.

So one of those persuasive speaker has been given the power of truth, that being...