Those who had perished in Vamdemon's invasion of Earth, whether killed by the Chosen Children or Vamdemon himself, had expected as they died that they would be reborn in the village of beginnings. None at the time had considered that they had traveled to a new world, and that the normal cycle of reincarnation depended on recycled data in the digital world; unable to enter their next lives, they explored Earth as ghosts.
Pumpmon and Gotsumon were probably the least unhappy with this outcome. Haunting Shibuya seemed as enjoyable as hanging out in Shibuya while alive, if a bit different. They didn't get yelled at or mistaken for human children in costume, but on the other hand, they couldn't taste ice cream anymore. They could float through walls, levitate, and hang upside-down, and this was nearly as fun a way to scare people. Gotsumon was particularly intrigued by the release of a recent handheld video game which portrayed Shibuya itself as a dangerous afterlife, but even had he been alive his three-fingured, rocky hands would have made playing it extremely difficult.
DarkTyranomon had also adapted surprisingly well to being a ghost. The computer virus which had driven him into Vamdemon's army as a walking weapon had been sealed by Lilymon, and he had no destructive urges without it, so he took advantage of this chance to explore a city – the digital world had its own cities, if never as big as Tokyo, but his large size meant that he'd destroy any he tried to walk through, and he had never taken the chance in earlier, smaller phases of his evolution. Being able to move through a city while incorporeal, at least at the start, was a dream come true.
Phantomon was used to being a ghost, and had been ever since he first reached the adult level as a Bakemon. He hadn't quite disintegrated and come back instantly, but not much had changed for him, except that he could no longer freely enter the digital world. The many Bakemon he counted as subordinates and sometimes even friends had a similar experience, but stayed well away from Buddhist temples and even Shinto shrines; they didn't want to hear that awful sutra ever again.
PicoDevimon, once so upbeat, was a traumatized shell of his former self. He wasn't the only one Vamdemon had killed - many of the others had met their death at the hands of their leader. But PicoDevimon had remained as loyal as any of Vamdemon's followers through and through, justifying the other deaths as punishment for treason or desertion; to be eaten by Venom Vamdemon after helping to bring him back to life was the ultimate betrayal, and he had never truly recovered from it.
Mammon, a vaccine digimon, had always been an odd fit in Vamdemon's army. He had joined not out of megalomania or a love of destruction for destruction's sake, but because of all the warlords in the digital world, he saw Vamdemon as a visionary, one who could overthrow the cruel and distant harmonious ones and the children they chose, and bring peace to the digital world at last. It was on Earth that he saw his folly; the city through which he had senselessly rampaged (to sow fear and ensure a quick surrender) was the capital of a country more peaceful, orderly, and just than any in the digital world. If he had to do it all over again, he would've fought alongside Garudamon.
DeathMeramon was happy to be a ghost; ghosts could not feel pain, and he was no longer burning. He spent most of his time haunting Tokyo Tower, which he had once bent with his body heat, although he was disappointed to find that it was not actually a portal to yet another world, as different from Earth as his own.
Tuskmon and Snimon had also been eaten by Vamdemon (and at PicoDevimon's urging!) but bore no grudges in that regard; they were already dying of their wounds, and had held on precisely to revive Vamdemon for revenge. They felt wholly out of place in Tokyo, so their spirits moved on to haunt the wilderness; earth animals might be dumb, but at least they weren't so alien, nor as ubiquitous as the millions of people in Tokyo.
Only Wizarmon maintained a strong tie to the world of the living. He had given up his life to protect Tailmon, but so long as she lived, his mission was incomplete. He was the first of them to notice that Vamdemon wasn't around, and far more perturbed by it than the others, who had assumed, whenever he raised his concerns, that their former master was too ashamed of his mission's failure and causing their deaths (directly or indirectly) to show his face.
Wizarmon was convinced of the opposite, for Vamdemon had cheated death at least once before, and was not the sort of digimon to simply disappear, ghost or no ghost. He eagerly sought out everything related to his killer, to Tailmon's abuser, but found so little he expanded his sleuthing to anything whatsoever related to the digital world.
He learned that the Digimon Kaiser was a true chosen child who had been led astray – much as Tailmon had been by Vamdemon, and perhaps this is what gave him his new-found determination. He learned of a cryptic prophecy, from the same sources as those which told of bats darkening sky; this one was much shorter, and said only that kindness shall unleash the golden radiance, which he spent even longer trying to interpret. He never quite discovered that Yukio Oikawa had offered his body as a vessel to Vamdemon in exchange for entering the digital world, but he had his suspicions – and he knew that, whether Vamdemon or someone else was controlling him, he imperiled the digital world and the safety of his beloved.
One by one, the other ghosts disappeared – perhaps to the village of beginnings, perhaps to the human afterlife. Whatever limbo they had been in had ended, and yet Wizarmon remained a ghost for three entire years, until Oikawa made his move and Tailmon could make sense of his warning. The first was spent in this research, the second and third in slowly increasing, foreboding loneliness, as his acquaintances disappeared one by one. Wizarmon was the last left, and once Mammon faded away, he resorted to pranks on the living, acting like a common poltergeist in lieu of any other human interaction.
On the third anniversary of his death, Wizarmon's ghost took over Fuji TV station, the site of his own death, to send a message to Tailmon. In doing so, he indirectly saved the digital world, earth, and Tailmon's life once again. And then, unable to even hold hands with a weeping Tailmon, the last digimon ghost left in Japan finally moved on.
