Astatine Gensetsu

Element 85. Named from Greek ἄστατος (unstable), the rarest naturally occurring element on Earth — less than 1g exists in the crust at any time. As the last halogen, it inherits the spear warrior tradition, but its weapon decays in 8.1 hours. Yet At-211 alpha therapy holds the power to kill cancer — a warrior who saves lives in her final moments