The V-X was a superweapon developed by Belka after the Circum-Pacific War. It was the first ever antimatter explosive ever concieved and actually worked (based on the explosion produced by the first one's self-destruction). If used, it could wipe out a third of the world's population, or about 2 billion people and could plunge the world into a nuclear winter lasting 10 years. As a result, the further develpoment of antimatter weapons was banned by the United Nations after the Osean Continental War in 2018.
There are only two known attempted uses of the weapon. Neither succeeded.
1. Launched on a specially designed ICBM at the end of 2017. Self-Destructed.
2. Loaded onto a space-borne warship , EASS Jormundgandr, at the end of the Erusian Civil War. Destroyed when Jormundgandr exploded.
It is as of yet unconfirmed whether the Belkan Waldreich has these weapons, but it is unlikely as all the file on the V-X were ordered destroyed in 2020.