"Venerable Duanmu" and another Spirit Transformation cultivator had to leave and assist in battle. They could not even wait for someone from the rear to come replace them in guarding this place, so Meng Zhiyuan's return might be delayed for quite some time.
Perhaps "Venerable Duanmu" had sensed something about the future at the time. Moreover, the Dark Spirit Demon Bats had faithfully fulfilled their duties here for hundreds of years.
At the same time, during his time guarding this place, the Dark Spirit Demon Bats had treated him with utmost respect and carried out every military order flawlessly.
Thus, before leaving, "Venerable Duanmu" decided to lend the Dark Spirit Demon Bats a hand and allowed several powerful members of their clan to choose for themselves.
One option was for him to bring Meng Zhiyuan back across realms after he returned.
The other was for him to use a great divine ability to seal the Dark Spirit Demon Bat clan within the land of restrictions.
"Venerable Duanmu" cultivated the Laws of Life and could control the passage of time.
However, even with his Spirit Transformation Realm cultivation, he had only a rudimentary grasp of the Laws of Life. If he merely wished to extend someone's lifespan by a few days, he could naturally do so at once.
But once he left, he might be gone for months or even years. To truly seal the flow of time, he had to borrow some vast power to accomplish it.
At the same time, runes had to be inscribed into the bloodline of the Dark Spirit Demon Bat clan, linking their bloodline to that power. As long as that power did not die, they would not perish.
And the place they guarded just happened to contain such a power. Yet as for what