Karoman said that these creatures were the pets of the Devil King. Apocalypse-grade ones were rather dangerous.
If these fellows really came to life after shattering the crystal, it was also a question if he could control them.
Although they were all pets of the Devil King, and, in theory, they should be considered Demonic Neonate's pets, who knew if they were still loyal to the Devil King? Even if they were loyal to the Devil King, they might not be loyal to Demonic Neonate. Furthermore, these fellows hadn't died in the battle against the Devils. That was problematic in itself.
"What's on your mind?" Karoman asked in puzzlement when it saw Zhou Wen staring blankly at the Nine Tribulations Devil Seed.
"I'm wondering if the fellows inside are dead. If they are already dead, they are treasures, don't you think?" Zhou Wen said with a smile.