
1) DC Comics alien 2) DC Comics martial artist 3) Extraterrestrial supervillain 4) Sibling musical trio
Found on
https://www.crosswordclues.com/clue/blackfire

==Fictional character biography== Komand`r was the firstborn child and eldest daughter of Tamaran`s royal family. The first princess born in over one hundred years, she should have been courted and showered with honors. On the day she was born, the Citadel Empire attacked and destroyed the western Tamaranean city of Kysarr and killed three thous.....
Found on
http://en.wikipedia.org/wiki/Blackfire

a disease of tobacco, characterized by angular, dark lesions on the leaves, caused by a bacterium, Pseudomonas angulata.
Found on
https://www.infoplease.com/dictionary/blackfire
No exact match found.