Unbeknownst to Surtr, a necromancer's black demon had desecrated his once pure flame. Soon after, his body gradually festered, and he lost all sanity. His black flame now burns even blacker than darkness itself.
Obtained as individual special reward during Soul Crusher event for repelling 30 bosses.
In Norse mythology, Surtr or Surt (Old Norse for "black" or "the swarthy one") is an elder jötunn. Surtr is foretold as being a major figure during the events of Ragnarök; carrying his bright sword, he will go to battle against the Æsir, where he will do battle with the major god Freyr, and afterward the flames that he brings forth will engulf the Earth.
In a poem from the Poetic Edda, Surtr is described as having a female companion, Sinmara. In a book from the Prose Edda additional information is given about Surtr, including that he is stationed guarding the frontier of the fiery realm Múspell, that he will lead "Múspell's sons" to Ragnarök, and that he will defeat Freyr. Surtr has been the subject of place names and artistic depictions, and scholarly theories have been proposed about elements of Surtr's descriptions and his potential origins.