The Wadatsumi Mass Vanish Incident (ワダツミ集団消失事件 Wadatsumi Shūdan Shōshitsu Jiken), also known as only Wadatsumi (ワダツミ), was an event that occurred ten years prior to the events of XBlaze – Code: Embryo, in which over 3000 people disappeared without a trace. A black storm suddenly appeared out of nowhere and engulfed a part of the city, leaving only destruction in its wake. As the Wadatsumi Laboratory was at the center of the cataclysm, the incident is often shorthanded to Wadatsumi. The site of the incident was named “Closed Special Ward” (閉鎖特区 Heisa Tokku), and it was forbidden for most to enter without permission. It has a diameter of two kilometers. No grass or plants can grow there. The cause for the Incident was the tempering of the Embryo, and the true form of the storm was the Grimoire of Origin using “Soul Eater” to collect magic element for the tempering. There were other casualties other than those that disappeared, such as Mei Amanohokosaka’s father, who had their souls drained. Less than 1% of the population survived the incident. When Ryōko Kagari stopped the tempering, the black storm spread out like crystals in the air, producing a mass increase of Unions.