Few Phantoms, let alone ordinary people, knew about the existence of the First Star. For everyone else, the Last Star was just a legend invented for one purpose—to explain the origin of their world, where energy came from, where monsters came from, and most importantly, where Phantoms came from.
Some believed that the Last Star existed, others did not. It was not that important, as it was all just theory.
Only the highest members of the government and the K4-Phantoms had accurate information that the two ancient stars, the Last Star and the First Star, actually existed.
Well, the new K4-Phantoms learned about this from their elders, just as it happened now between Adam and Wilfred.
What reasons did they have to believe the words of their elders?
It was very simple. There was evidence of the existence of the First Star and the Last Star. Oddly enough, it was not the Midnight Crystals and the Twilight Crystals.
