WARNING: Spoilers ahead for Supergirl: Woman of Tomorrow #5

The DC Comics universe is filled with all sorts of dangerous forces, with the unstoppable Doomsday occupying a spot near the top of the list, but now, Superman himself has confirmed to Supergirl that there’s one threat that’s just as deadly as the beast that killed him. Kal-El of Krypton is one of DC’s most powerful heroes, so any threat that he considers to be so grave can’t be an exaggeration. But while most of the forces Superman fights are malevolent entities, this newest danger, called Barenton, isn’t just another alien despot – it’s an entire planet.

Although Barenton isn’t consciously evil, it’s still a danger unlike any other in DC Comics lore. Confirmation of this incredible threat comes by way of Supergirl: Woman of Tomorrow #5 by Tom King and Bilquis Evely. And unfortunately for Superman’s cousin, the titular Supergirl, this issue sees Kara learning firsthand just how dangerous Barenton can be.

Related: Supergirl Just Proved She Really is Tougher Than Superman

After tracking down the criminal called Krem of the Yellow Hills, Supergirl and her companion Ruthye are magically teleported to a mysterious world that seemingly weakens the Woman of Tomorrow. After narrowly escaping the local wildlife, Supergirl tells Ruthye she knows exactly where they are and explains just how much danger they face. Declaring they’re on the world called Barenton, Kara says it was a deathtrap built for her cousin with deadly amenities like a green sun, Kryptonite, and deadly monsters. In describing her cousin’s last visit to Barenton, before he was rescued by the Justice League, Supergirl tells Ruthye that Kalndescribed it as “the most painful experience” and “the closest to…death..he ever got,” even after his literal experience with death at the hands of the creature Doomsday. Although Kara and Ruthye do escape Barenton, Superman’s description of the world paints a haunting picture of its true threat.

Clark Kent isn’t prone to exaggeration, so the level of danger he’s associating with Barenton shouldn’t be considered an overstatement. With a green sun, dangerous monsters, and even Kryptonite, this world is a perfect trap for Superman, Supergirl, and any of their fellow Kryptonians who find themselves unlucky enough to find themselves there. And any place that can incapacitate a Kryptonian could potentially hold all sorts of untold dangers for anyone on a similar power level, including heroes like Shazam or Wonder Woman.

Supergirl lasts on Barenton far longer than Clark ever did, but that doesn’t negate the danger of the weaponized world. Though she eventually escapes, Barenton very nearly killed a Supergirl, who’s long been established to be tougher than her more famous cousin. And the fact that Superman describes this world as the closest he’s ever come to death - even after his literal death at the hands of Doomsday - speaks volumes about the type of agony this world inflicts.

Doomsday may have been the monster that killed Superman, but the planet Barenton hurt him that much more. And while Kara does manage to escape its treacherous confines, it’s clear that such a feat isn’t something any DC Comics hero can take on lightly. With any luck, Superman and Supergirl will be able to steer clear of Barenton from now on - or else, like Doomsday, it may well be the death of them.

Next: Supergirl's Powers Mean She Lives Her Entire Life in Pain