Inside the Mirror Dimension, as Li Feng opened the wooden box in his hand, several Dementors were driven into a corner by the deadly energy radiating from the Pseudo-Angel Feather. They trembled as they let out agonized wails that only Li Feng could hear.
Only when Li Feng felt that the Dementors might truly die if they were exposed to the Pseudo-Angel Feather any longer did he close the wooden box. "Now, those who choose to submit, kneel and sign a Slave Contract with me. Those who want to die, just say so. I'll grant your wish."
The strong preyed on the weak—it was nature's fundamental Law. Between survival and death, the Dementors naturally chose survival, just as they would later choose to serve Voldemort.
Li Feng did not know how Voldemort had subdued the Dementors, but it had been nothing more than threats of force or some kind of temptation. Now, Li Feng merely demonstrated that he could kill Dementors, and they lowered their heads one after another, waiting for him to carve the contract upon them.
Having subdued the Dementors within the Mirror Dimension, Li Feng impatiently opened a Portal and commanded in Necrolanguage, "Now, capture every Dementor that hasn't signed a Slave Contract and bring them in."
The enslaved Dementors nodded slightly and replied in Necrolanguage, "Yes, Master."
With that, they returned to the real world through the Portal, while Li Feng only needed to wait inside the Mirror Dimension for his newly acquired servants to drag the Dementors in one by one.
At first, Li Feng feared that he had too few servants. Once the captured Dementors realized what fate awaited them, they might resist. To be safe, he maintained the Mirror Dimension. After several "wild" Dementors were thrown inside, he closed the Portal to prevent