The world had become more sinful to the point the Legendaries didn't dare show their faces. They could feel the evil expanding, and feared it was going to reach them as well. This fear was what caused them to start wilting from their high positions. As pollution became thicker and more prominent, Celebi was struggling to keep plant-life prosperous, resorting to using his life-source to do so. The last time Ho-oh saw him, he was beginning to turn a color of rot. The eyes were still bright, but it wouldn't be long before they would dim. Jirachi, many years back, had eventually broken free of his sleeping spells and began to use stored energy from the Millennium Comet as his powers. However, because he never knew of the real world, it became a gut-wrenching experience for him. His cheerful face transitioned to a blank mask within months of the realization, and then his wishing powers depleted over time. Darkrai, though he lived off nightmares, was being possessed with demons from the people he tried to haunt. It grew difficult for him to find true fear to feed, and he fled to isolate himself away from civilization. Even Giratina had to get away from the world, and would only come out of his dimension if the Legendaries really needed him.