It's powerful enough to match Negi's Khilipl Astrape. Besides magma, it's also shown to include control of quicklime and, in Dodai's case, rubber (or at least lava that he can make very rubber-like). Naruto later gains it himself after absorbing Son Goku's chakra along with those of the other Tailed Beasts. Mei Terumi (the fifth Mizukage), Kurotsuchi (the granddaughter of the Third Tsuchikage), and Dodai (an elder shinobi from the Cloud Village) were all born with it, and Roshi has it by virtue of Son Goku (the Four-Tailed Monkey) sealed inside of him. Harry/Halley Tribeca developed it as a secret trump card to use against Victoria or Sieglinde, but she was forced to use it against Rio when Rio managed to back her into a corner.
A character in The Law of Ueki converted tomatoes to magma.
