Madelyn Pryor AKA The Goblin Queen

One of the most dangerous enemies The X-Men have ever faced, Madelyn Pryor, also known as The Goblin Queen. She played center stage in the Inferno storyline that was a Marvel Comics company-wide crossover in 1989 that mainly involved the mutant titles, namely Uncanny X-Men, X-Factor, X-Terminators, Excalibur, and The New Mutants. The story concerned the corruption of Madelyne Pryor into the Goblin Queen, the final transformation of Illyana Rasputin into the Darkchylde, the demonic transformation of Hobgoblin, and a demonic invasion of New York City. The series was written by Louise Simonson, Chris Claremont, Steve Engelhart, Gerry Conway, David Michelinie, Ann Nocenti, Walter Simonson, Jon Bogdanove, Terry Austin, and Julianna Jones.

And in my opinion, one of the best storylines Marvel has published, and as long as Disney owns the IP, you'll never see it.....1989, damn I'm old, I remember picking these books up as a kid as they came out, those were good times for comics.