"Twelve-Winged Dark Seraphim" is not a single character with a biography, but rather the pen name of the author of the popular Chinese web novel series Super Gene.
As an author, their personal biography is not widely publicized; they are known primarily through their published works. The name "Twelve-Winged Dark Seraphim" itself is likely a creative pseudonym derived from the concept of Seraphim, a high rank of celestial beings in traditional Abrahamic religious texts, who are typically described as having six wings, with the "twelve-winged dark" aspect an original addition by the author.
