Many centuries passed since the Sudden Shift; lots of humans and animals now roamed the earth. Humans utilized every resource they had. They started hunting. But some can't hunt because of the season, so they started farming. To better transport their goods, they tamed the animals. They made houses made of wood and soon found ways to make them out of stronger materials.
Fast forward to the present, the world has entered the industrialized age. Electricity now runs the world. Tall buildings, fast vehicles, and a systemized way of living. But what's more amazing is that some people seemed to hold special abilities, abilities that most don't have. Some have the ability to fly, some can breathe flames, and some can run very fast. People call them "Power Holders."
Normal humans idolized these people, and justifiably so. Power holders helped the world go forward. Power holders helped in inventing new things, made buildings, and, most importantly, enforced laws. Some Power Holders used their abilities however they liked, and it is the Power Holders on the justice's side's job to stop them. They are basically heroes and villains.
Power Holders gain their abilities by eating a fruit, a mystical fruit. These fruits came from the mystical tree that stood out among any other tree on every island, called the Power Tree. Nobody knows where it came from or how it came to be, but many believed it was during the Sudden Shift, but nobody can really prove it. What's important is that, because of these trees, the life of the humans became much easier, at least on the surface. Each Power Tree produces a different power fruit.
In this new world, power triumphs over anything. If you have no power, then you are nothing.