Man I had that super-sized (it was LARGE in my kid eyes, not sure how big IRL but way bigger than the normal comic format) Superman vs. Ali comic book and I LOVED it. I wore that thing out to death. I don't remember the whole story but some kind of convoluted setup had superman boxing Ali on a spaceship to save Earth but superman didn't have his powers because of... kryptonite? the wrong color of sun? something LOL