Since before he even became an apprentice in 782, Eric had always loved stories from Earth involving mermaids. (He is also said to have been inspired by "The Tempestuous One," one of Tooblan's plays.) He had always wished he might someday bring merfolk into existence on the Land, but the incident of the banishment of Roderick and the First 50 Elves in 773 made such a thing seem hopeless. That is, until Nyza succeeded Cazzul as Grand Sorreter in 791. By this point, Eric was an adept, just as Roderick had been when he created elves. However, Eric felt he should refrain from making his hopes known to anyone until he became a master-adept, which he did in 800 (and in that same year, obtained a seat on the Council of Magicks. His hopefulness concerning his planned project had been increased the previous year, when Arch-bishop Prax was succeeded by Darren, who was known to be a free thinker.
However, Eric had never allowed himself to do much in the way of any serious planning of how to go about creating merfolk, being afraid it wouldn't even be permitted. So it was only now that he began figuring out how it might be done, and eventually he realized he was definitely going to need help. And before asking anyone, he thought he should establish a better standing for himself on the Council. Finally, in 807, he went to Nyza and asked her permission for his project. She agreed, but said that first they'd have to ask Darren about it. He was in favor of it personally, though he had no official position as Arch-bishop. He also felt most bishops would be against the idea. Nevertheless, he gave his tacit approval, and Eric began his project, with the help of the Council of Magicks and various adepts. They finally achieved their goals with the creation of the first generation of merfolk, in 810. The new species became the third to be classified as fully intelligent.
However, in the same year that the project reached fruition, Darren died, and was replaced by Arch-bishop Ignico, who was decidedly against the creation of merfolk. He could take no action, both because the project had already been completed and because it had been conducted openly and with the support of his predecessor. And so, in 811, Ignico banned any future creation of mythical creatures, intelligent or not.