On his first night in the instance world, Wang Zhifan did not cultivate as usual, nor did he travel around gathering more intelligence. Instead, he immersed himself in observing the infinitely many fate lines revealed by the Ring of Fate.
He discovered that, just as he had inferred, the Demon Kings would descend upon this world together after some time. As for exactly how long, some fate lines showed one or two days, while others showed a month later. He did not know what crucial factor determined it.
It could be inferred that this period was specifically meant for players to prepare, whether by understanding this world or gathering intelligence on the Demon Kings. Once the Demon Kings descended together, the true high difficulty would reveal itself.
"My plan is to eliminate every Demon King, so gathering intelligence on all of them is important. But at present, I only know of the Hellfire Demon King, and all I know is that it controls strange flames... It seems I do not need to speed up the Demon Kings' descent. I should give myself more time to gather intelligence on them. There is no need to slow their descent either. The cost of doing that would not be trivial. I'll let nature take its course."
Having settled that matter, Wang Zhifan left Silverkeep that night and began traveling through this world to investigate it.
He had long since acquired several versions of the world map, both from before and after the disaster, so his investigation was far more purposeful and strategic than when he had first arrived.
There was no need to describe the process in detail. In short, after investigating many places, Wang Zhifan learned the names and general power attributes of seven Demon Kings. Aside from the Hellfire Demon King,