The World's End has already turned into the former "Golden Kingdom" site of Olivia, the "Mother of Roses."
In that place that is not entirely in the Material World, but somewhat like the "Sanctuary," semi-independent from the Material World, a small world.
A giant tree, whose roots are deeply embedded in the seabed, whose branches and leaves obscure the metal "Gate," has replaced the entire "Golden Kingdom."
Even if the entire Material World is in chaos, here remains a tranquil paradise, as if a human fairyland, a haven outside worldly affairs.
"Legend has it, in a certain country, there was a well that had become polluted. If you drink from it, you would become 'mad,' and behave differently from before.
When all the citizens had drunk from the well, yet the wisest king had not, then the behavior of the majority became the societal norm.
So, the people thought they were normal, and only the lone king was mad.
