As the Natural Demiplane grew bigger and bigger, a lot of laborers were required for tasks such as growing plants, dredging canals, and repairing buildings. If nobody was responsible for such tasks, then the Demiplane would turn desolate, and the tiniest error might lead to abnormalities in the Demiplane. Therefore, the number of laborers had to be guaranteed.
Those Blood Elves were the best candidates. They fed on the power of blood, and didn't need regular food. After their mana was sealed, the mana inside their body would be the source of their strength. They didn't need any food, and as elves, they were very talented in art and architecture.
Those Blood Elves were perfect laborers. There was no need to worry whether they could cause any trouble in the Natural Demiplane.
