YMMV / The Condemned Legionnaires

• It Was His Sled: Satan Girl's identity was a mystery when the story was published in 1963. Several decades later, who has heard of this story knows the Evil Doppelgänger twist.
• Older Than They Think: Most of Superman fans are unaware that this story introduced the idea of Kryptonite being also harmful to humans, predating the "Lex Luthor's Kryptonite ring gave him cancer" plotline for nearly thirty years.

---