Avengers, The #131 (1975) First Print

"A Quiet Half-Hour in Saigon!" While the Avengers continue to aid Mantis in learning her true origins in Vietnam, in the realm known as Limbo, Immortus has rescued Kang and Rama-Tut from outside of time. Offering to aid them, Immortus is instead betrayed by Kang who imprisons both Immortus and Rama-Tut. Kang then uses Immortus' devices to gather his "Legion of the Unliving", super-beings from different points in history, plucked out of time moments before their deaths and put under Kang's control. Among those selected are The Frankenstein's Monster, the original Human Torch, Wonder Man, Baron Zemo, Midnight, and the Ghost. Back on Earth, Mantis is startled by the appearance of a spectral image of Swordsman, however before the Avengers can try and learn what's going on, they are all plucked out of the present and transported to Limbo inside the fortress of Immortus to do battle against the Legions of the Unliving.