Short answers, pulled from the story.
Capcom released Darkstalkers: The Night Warriors in Japanese arcades in 1994. This release marked a departure from the realistic martial arts style that dominated fighting games at the time.
Pyron is an alien overlord who returns to Earth after many years away to conquer the world using an army of robots. His return forces the Darkstalkers out of hiding to oppose his rule and battle for dominance over the night.
Anakaris was once a pharaoh before being revived as a mummy by Pyron, while Jon Talbain is a British werewolf who uses nunchuk-based martial arts to escape his curse. These figures were not humans but monsters drawn from international folklore.
Madhouse produced four episodes of the anime miniseries Night Warriors: Darkstalkers' Revenge under license from Capcom with direction by Masashi Ikeda in 1997. An American animated series aired from September to December 1995 on broadcast syndication.
By March 2011, Capcom had received over 100,000 requests for a new installment of the game. Yoshinori Ono stated in 2007 that he wanted to resurrect the series for new technology.