The Aetheria are the only intelligent species to inhabit Jotunheym. They were also known as Tuohocan, Omeyocan, and Nethocotz by the different races they've had contact with. With an expenditure of energy and effort they can manifest in Midgar. In order to assist with this process and allow races native to midgar to initiate communication, the Aetheria built nexuses on various planets in different galaxies. These nexuses were gigantic pyramids that concentrated lepton radiation into crystal skulls. When a person stares into the "eyes" of the skull, they are engulfed in radiation and partway transitioned into Jotunheym. The skulls were modeled after the species they were made for, in the Ida galaxy the skulls were in the shape of Asgard skulls, while in Avalona they were the shape of human skulls.
The Aetheria are allies to the Alterra, and nominally to the Asgard as well, although there is bad blood between those two races. The Aetheria like to play pranks on the Asgard when they get the chance. While it might be a game to the Aetheria, the Asgard do not enjoy being put in mortal jeopardy for the amusement of others.