Warning! Spoilers for Heroes Return #1 by Marvel Comics below.
Marvel Comics previously teased Hyperion was particularly vulnerable around Captain America for mysteriously unknown reasons - and now, they've given an answer to why: Marvel's Superman's kryptonite is vibranium. In the grand finale of the Heroes Reborn event, Hyperion faces off against the Avengers. Fighting in Wakanda, he immediately starts to feel weak. When he falls to the ground, it becomes clear what the character's true weakness is.
Marvel's Heroes Reborn event has come to a close, as it's been revealed Agent Coulson and Mephisto are responsible for rewriting reality so the Avengers don't exist. Coulson's changed world made the Squadron Supreme - Marvel's pastiches of the Justice League - the top heroes in the galaxy. While the Avengers were slowly reformed and learned the truth about their surroundings, Hyperion was shown to be weak when next to Captain America. It turns out, Marvel's Superman isn't just weak against Steve Rogers, but vibranium is his kryptonite.
In Heroes Return #1 by Jason Aaron, Ed McGuinness, Mark Morales, and Matthew Wilson, the Squadron Supreme and Avengers face off in one final slugfest. As Captain America goes after Agent Coulson and his hellish Cosmic Cube, Thor and Hyperion exchange powerful blows at each other. Hyperion realizes he is growing weaker with each punch he's throwing and Thor notices vibranium is actually affecting his powers. Thor tells Hyperion his biggest weakness is mead and says he knows this now upon seeing him struggle in Wakanda.
In a later conversation with Nighthawk, Hyperion admits he thinks he broke both his hands as his teammate tells him he "looks like Hell." In a clever piece of writing by Aaron, Nighthawk reveals he knew about his weakness, as the vibranium actually came from Hyperion's homeworld when it exploded. He notes the radiation inside could kill him. The Avengers eventually regather, take down the Squadron Supreme, and destroy Agent Coulson's cosmic cube, resetting reality to how it once was.
With reality is restored to its former self, it's extremely unlikely that Marvel's Superman kept the same weakness as he did in Coulson's world. But still, making vibranium Hyperion's biggest weakness is both a great nod towards Superman's Kryptonite and a perfectly valid explanation to why he was weaker against Captain America early in the series. Marvel's Heroes Reborn was one of the most fun events the publisher has done in a long time - hopefully, it's not the last readers see of this world and Hyperion doing his best Superman impression in the Marvel Universe. Heroes Return #1 is in stores now.