While Leviathan was showing Shadowslash the changes that had happened on Invincible Kingdom during his absence he on the other hand was checking places or location that he could inscribe inscriptions.
The starting point of his Invincible Kingdom is actually much better than his other two kingdoms because its Mana and spirit Qi purity and density is above average.
But because it was still on building phase before he left he didn't immediately increased the density and purity of the spirit Qi and Mana.
Not to mention the clams, corals and the other treasured beasts that he left in this kingdom is already enough to transform the entire place.
Now after an amount of time the entire kingdom is already comparable to most precious ground of the sects back on Beast Continent.
