I had always believed the Nail to be a star, close in proximity to the Earwan solar system. However, I didn't catch on the the whole Cunoroi name of the New-Born before. Maybe it's just a star that went super-nova. I'm finding that one difficult to explain, though, since it just happened to go nova in the exact polar north of Earwa, relative to the planet's rotation. Coincidence? Maybe not. Maybe the Inchoroi go from system to system with some expansive galactic map, scribing their journeys from planet to planet in a great mathematical sigil of destruction. Maybe the Nail was their last conquest, and it pointed the way to their next: Earwa. How long would a star appear brighter from going nova? I'm probably wrong about that, but fun to speculate.