They were children of a God.
Kosmos and Kronos were the link between the human and digital world.
The Genome Corporation in the public eye was the leading computer research and genetics corporation in Japan. They provided citizens with products that in turn, made their life easier. They were powerful, yet corrupt. Behind closed doors, the Genome Corporation dealt in human experimentation and cloning. In the beginning, they were the ones that had funded Yukio Oikawa's 'Akuma Project', which was never completed.
The Akuma Virus wasn't completely destroyed in the battle with the digi-destined in 2005. Instead, weakened and in a semi-slumber like state, he was left to drift through the internet until his energy depleted and he faded from existence. But deletion never came.
The Genome Corporation was able to track down what was left of the Akuma Virus and contain it for continuing research that began in 2005.
Through a combination of human DNA injected with the Akuma Virus, Kosmos and Kronos were born. Twin children of the most power virus to ever exist.
But humans should never play God.
Unknown to the scientists who monitored their growth each day, Kosmos and Kronos held a telepathic link to the original Akuma Virus which was being held in the same facility as them. He gave them information of the outside world and the digital world and because of this, they longed for freedom. Eventually their telepathic link grew and they could hear the thoughts of the scientists around them. They discovered that all they were were property. The Kosmos and Kronos were experiments in a research project that was to be terminated in 2025. Termination of the project meant termination of the test subjects as well.
Kosmos and Kronos were growing too powerful to handle. Like their father, both of them were weak towards light and so, they were constantly kept in highly lit containment chambers to keep their power level down, and making escape next to impossible.
Yet in 2024, a year before their termination date, Kosmos and Kronos were witness to a nightmare. During one of the times when they were being held in one of the light chambers, their minds listened in horror at the screams of their father who was being experimented on. His howls echoed through their minds, and both of them finally snapped. The lights burst in showers of glass, leaving absolute darkness in the lab.
Soon the screams of their father were replaced by the screams of humans which were soon silenced. There were no survivors and the test subjects escaped along with the original Akuma Virus into the digital world.
The Order
Japan itself was a country who's people were influenced by the rise of cults and religious movements. The Genome Corporation kept the incident within itself and away from the Japanese people, yet this silence was short lived. Soon, people around Japan were recieving e-mails from "The Order" that soon spread into a recognized cult among Japan's people. It was still quite small, yet extremely disturbing.
The e-mails that were being recieved described that humans were pure evil and were destroying the planet. The only way to end the pain of the world was to return to the never-ending circle of energy that was in the care of the Great Lord Akumamon. Within that energy, there no longer would be any pain or suffering.
Kosmos and Kronos were manipulating the internet so that e-mails were sent out around Japan, watching with delight as humans fell easily under their control and followed their every command.
The Digital World was the same. Many Digimon followed The Order, led by the hybrid Twins in the hopes that Akumamon would return to power.