The Emerald Empress is the name of several, fictional super-villains appearing American comic books published by DC Comics. The characters associated with the name are often portrayed as a prominent adversary of the Legion of Super-Heroes. The first incarnation of the character appeared in Adventure Comics #352.
Emerald Empress as depicted in Supergirl #8 (2017); art by Emanuela Lupacchino (penciler), Ray McCarthy (inker), and Hi-Fi Design (colorists).
Emerald Empress as she appears in Legion of Super-Heroes
The Fatal Five is a supervillain team of the 30th century in the DC Comics universe. They were created by Jim Shooter and first appeared in Adventure Comics #352 (1967) as enemies of the Legion of Super-Heroes.
Cover to Adventure Comics #352, art by Curt Swan.