Ulnar (or The Temple of Unification) is a massive xel'naga temple located in the Alterian Rift. It was the resting place of the xel'naga, and served as a portal leading to the Void. A massive amount of Void energies emanate from Ulnar. As far as the laws of physics go, Ulnar should not exist. It defies even the protoss's understanding of astral mechanics. And yet, exist it does. Karax was able to determine the Keystone's origination point - Ulnar, legendary homeworld of the xel'naga. He tracked it to the Alterian Rift, and believed he was in error, for nothing should have been able to survive there. Artanis, however, was not so despondent, for protoss legends stated that the xel'naga originated from a place where no life should be. He ordered that the Spear of Adun enter the rift. It was a decision that validated Artanis's faith, and the Spear of Adun arrived at Ulnar, a giant structure that existed within the rift. Karax deduced that this was the Keystone's primary purpose, to act as a mechanism to lead its user to this place. He commented that Ulnar should not exist under what the protoss understood of astral-mechanics. And yet, it existed all the same. 'Starcraft 2: Legacy of the Void' PC game. Watch more Starcraft videos:.