Superman Unlimited #1, Superman pushes a city-sized kryptonite asteroid away from Earth, an act that results in him gaining a form of immunity to green kryptonite, which manifests as a new golden radiance under spectrographic lights. This transformative event permanently alters his relationship with his greatest weakness, though it creates a new global threat for other Kryptonians.
The initial threat: A massive, kryptonite-infused asteroid is detected on a collision course with Earth. The Justice League sends Superman to intercept it in space.
The struggle: Despite being weakened by the asteroid's kryptonite radiation, Superman pushes it away from Earth. He collapses from the immense effort and is later rescued by the Justice League.
The global consequence: Although Superman successfully diverts the asteroid, its impact still showers the entire planet with kryptonite, making the previously rare element readily available. This leads to a worldwide "Green K" arms race, where villains and even petty criminals can acquire kryptonite-based weapons.
Superman's transformation
The awakening: Superman spends three months recovering. When he awakens, he finds he has survived the otherwise fatal exposure.
The new ability: Batman uses spectrometer lights to reveal that Superman's body now emanates a golden light, a manifestation of his newfound resistance to kryptonite. In this state, he becomes invulnerable to the radiation that once crippled him.
A unique change: The resistance makes Superman fundamentally different from other Kryptonians, including Supergirl and Superboy. While they remain vulnerable to the proliferation of kryptonite, Superman is immune, creating new challenges and a different role for him.
This comic is straight from CGC and it has a mark on the front. I'm taking 10% of what I think it worth. Enjoy Comic Book Lovers!