Be the change you want to see in the world

"I tell the future"

"Okay, tell me mine"

"Soon... You will go to Rome."

"But I'm in Rome."

"Do I lie?"

Ah yes, the self-fulfilling prophet.

What's that story with the Wizard who cursed a family to die by thirty then broke into their homes to kill them when they turned 30?

The Dune school of divination

In Gym of the Romantic Journey, there was a character who could see the future, and then bring it about. Once he shot someone with a paintball gun because someone was going to wipe him off with a paperclip, and they'd look silly if he didn't have paint on him. And once he rushed into a room where a fire started, and then was relieved that he didn't have to be the one to start it.