Leon had to ask Jet if they could take a break. It was too difficult for him to process the information given by Dibella while walking around. All of this was mind blowing news. The thing that had touched him the most was that when he asked Rebecca to explain a few more things in detail, he was able to find out that during her time, there was no System!
This was shocking news that changed the way he looked at things. Perhaps Dibella's time and the battle between Michael and the Gods had marked the end of the Era of Gods. And to usher in a new era where they would not be challenged, the System was brought in. He believed it was an effective way to keep an eye on the progress of everyone, but even then, it must be an absurdly difficult thing to do. What kind of monster could handle such load?