So he was pulled forward through time... That explains why he knows about dragons in so much detail. Dragons began being hunted for sport around two centuries ago, now: for all he knows, Wan could be from hundreds of years in the past. But that was a discussion for another time.

"If you're able to enter the spirit world, why not combine your efforts with Korra and have a joint search? There's a young airbender named Jinora who is also very proficient in spiritual matters. She could be able to help, as well."