Mirthin

Last known surviving gnome.

He is shown to be capable of communicating telepathically with all the inhabitants of the local world at once (tens of thousands to millions of people).

He lives in a large tower that seems to teleport at random, with various mysterious properties. The ground level entrance leads into a large circular room, which itself has various entrances to similarly shaped and sized rooms, despite the first one being more than enough to fill the inside of the tower. These other rooms are in fact the upper floors of the tower, which can only reached in this way, as there are no stairs or ladders, or openings of any kind on the ceilings and floors.

Hypothetical

Considered insane by his people, he was the only one to stay behind [when the end of the Worldplane was prophecisied / after human mortality was shown to be insurmountable, wanting to stay and observe his children].