Yi Chen's body had long since reached perfection under Teacher Zed's tutelage. Combined with the anchoring effect of the spikes on his fingertips, climbing the cliff face with its prominent protrusions was effortless—only slightly more troublesome than walking on level ground.
The abyss was impossible to measure. Even as Yi Chen gradually increased his climbing speed, he still couldn't sense the bottom, and had no idea how long he would need to climb.
During his spare time, he chatted with Thirteen on his back.
"By the way, Thirteen, do you know how the abyss in the Extreme Dark Zone was formed? And roughly how it differs from the Original Tomb Abyss we're climbing right now?"
"I know a little about it. I learned it all from my former master, who was also my creator... The abyss is a special region formed under extreme darkness, and it's also a 'loophole' in the Old World.
"The abyss corresponding to the Original Tomb was formed because the Realm of the Dead had lacked sunlight for a long time. The abyss isn't completely unknown—instead, it's basically controlled by The First Dead, making it safe and stable.
"After the Evil Sun fell, most of the abysses that formed in the corners of the Old World fell into an uncontrolled state.
"Although a very small number of abysses have been explored by the Sick Ones, who have even converted the uncontrolled energy hidden within them for their own use, most abysses remain unexplored. They contain countless war relics and are uncontrolled and chaotic, but they're also filled with opportunities.
"At present, many Source Plague Zones in the Old World and special organizations have invested a great deal of effort into exploring and developing the Extreme Dark Zone.
"Ignacy, the City of Lights, became one of the