Super Friends

Superfriends: Rest in Peace (3x30)

Air date: Dec 16, 1978

The Legion of Doom unearths a crystal called "Noxium", created by one time member Dr. Natas. The Crystal can kill all of the Super Friends using emulations of their weakness such as Kryptonite, Yellow Power or lethal energy only to find out too late they were in hiding and had really killed off their clones.