Stone-cast walls, black iron walls, immortal steel walls.
Each wall was sturdier than the last, each thicker and heavier than the last.
Yet the first wall, cast from stone, had held back those Outer Dao Puppets for nearly seven thousand years, while the black iron and immortal steel walls combined had resisted the Outer Dao monsters' encroachment for barely half a year.
Meanwhile, something even more terrifying happened.
After the Outer Dao monsters breached the immortal steel wall, they gained yet another new property.
They could manifest "immortal steel" armor over their bodies.
After three evolutions, the Outer Dao monsters could already tear Spirit 통 Realm cultivators to shreds through physical strength alone. In just three short years, they destroyed the Azure Crossing Continent of the fifth reincarnation.
This, too, showed just how swiftly the Outer Dao advanced.
Next came the sixth reincarnation.
During the sixth reincarnation, besides ensuring that the world's peerless geniuses were born as they should be, Chen Yan also tried to eliminate the causes that might lead the Outer Dao monsters to evolve prematurely.
If he could find a countermeasure to delay the Outer Dao monsters' evolution, there could be no better outcome.
In truth, however, Chen Yan could make no predictions at all.
The Outer Dao itself transcended karma. This was also the real reason both the Heavenly Monarchs and Chen Yan agreed that the Outer Dao most likely belonged to the fourteenth realm.
Chen Yan continued sealing off the Outer Dao in the small village on the outskirts of the Silver River Mountains, in the Far Eastern Lands of the Azure Crossing Continent, all the way through the tenth reincarnation.
In other words, he made six attempts.
Throughout these six attempts, their duration was utterly unpredictable. This randomness also convinced Chen Yan that his