An unstable drakaina made from the cursed metal that kills anything that dares come even close was free and hunting Arad down.
Arad knew just how dangerous she could be. When he breaks matter down to use his energy breath, he usually gets cursed a lot, irradiated, as the Metallic Queen calls it. If he stood in one spot, anything in a hundred kilometers away from him would die instantly, and anyone beyond that up to a thousand kilometers would start getting sick, puking, rotting alive, and eventually dying a painful death.
If Arad wanted to, he could turn into a monster that no living being can even approach, let alone fight. So based on what the Queen said, that drakaina's radiation is so powerful that this entire world would be like it was in Arad's one-hundred-kilometer range.
Gamond, as an elder, had frozen an entire world, so a Uranium drakiana would irradiate the entire world and kill everyone just as painfully.