Bates, Swan and Jack Abel begin a 2-part “Imaginary Story” in World’s Finest 178 (Sept. 68), which sees Superman adopt a new identity, that of Nova.
On a space mission, Superman flies through some funky psychedelics, which strip him of his powers permanently.
Superman spends a while trying to re-charge them, then mopes. He sees Green Arrow and Speedy performing at a charity function, and this inspires him to become a costumed hero even without powers. Despite Green Arrow’s presence on the cover, his entire role in this story consists solely of this scene.
Later, Batman winds up sparring with a new hero, Nova. The only thing Nova has going for him is a cape that is indestructible. Batman defeats Nova anyway, and unmasks him. It’s Superman.
Batman attempts to convince Superman to give up on being Nova, but Superman falls into the hands of a mob boss.
The story concludes in the issue after next. 179 was a giant reprint issue.