Shina

A guardian of the earth and a powerful superhero, Shina has the power to absorb radiation to fuel her superhuman strength and size, with her growing to nearly a hundred feet tall after visiting Chernobyl. She shrinks as she processes the radiation until she returns to her normal height of six feet tall. She's recently fought with a powerful kaiju, whose radioactive breath attack made her grow to a little over two hundred feet tall. She's rather put out as it'll be weeks before she returns to her normal size.