Nyctalope is a French superhuman who possesses an artificial human heart and has the abilities of seeing through darkness and breathing underwater. He became a member of Les Hommes Mystérieux. Nyctalope and Mystérieux fought the English League at the Paris Opera House, in which he hunted down Mina Murray beneath the Opera before being shot in the chest by A.J. Raffles. However, Raffles failed in penetrating Nyctalope's artificial heart and his wounded form was rescued by Mystérieux.
The Nyctalope was created by Jean de La Hire and appeared in sixteen novels from 1908 to 1954. He is the adventurer Léo Sainte-Claire (Jean de Sainclair in some novels), who fights a wide variety of exotic evils with the help of a stalwart band of assistants. He's the first superhero of the genre, followed by the Japanese Ogon Bat, Superman and Doc Savage in the 1930s and, later again, Batman in 1939.