Well, her first appearance anyway. She called herself “Madame MacEvil,” and, IIRC, she put poor old Sub-Mariner threw all kinds of hell. I can almost remember the cover where she is casting an evil grin saying, “Come on in. . . They dying’s fine.”
Or maybe that was some other cover.
Anyway. . .
Later she was called Moondragon, and was revealed to be the daughter of Drax the Destroyer (at least his erstwhile earthly incarnation). Did they ever explain why she was such a bad guy the first time around, and ended up coming over from the dark side?