Osprey lives something of a reclusive lifestyle, making his home in a small demiplane, whose portal door he always carries with him.
Those who do know of him, know him to be one of the best lorekeepers of interplanar history, despite his young age.

The reason for this is that Osprey is a class of being known as a "true believer", a being with mild reality warping powers, whose subconscious belief about how the universe works, and how history progressed, will subtly alter the planes around them to reflect their belief.
As his ability is merely passive, he is unable to alter things "to his will". Instead, when chronicling or adapting an account of history (especially events with conflicting accounts), his record will be the most accurate, as past events will shift to match what was written.

His changes have never been so grand as to completely alter the course of history itself, or perhaps the effect is free of causality, and as a result doesn't suffer the consequences of the butterfly effect. Either way, many factions have their eyes on him, hoping that they might manipulate his abilities to change history in their favour.