He participates in saving the world during a time similar to ours (although a bit in the future)… somehow (enter fantasy) his flashlight works thousands of years later.

The King you refer to is the King of the Silver River, a fairy being who has been on Earth since the Beginning. He was given the Gardens of Life by the Word and in this place all life begins before it goes out in to the broader world. He makes an appearance in most books. He carries a flashlight because he facilitated…