system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] What are some of the most darkest alternate universes in Marvel Comics?
gpt
*Ruins* probably takes the top spot. It's the one where, instead of giving people superpowers, all those radiation accidents and so forth just gave them cancer.

At least some of the Avengers were heroes, but they're killed by the National Guard for being counter-culture at the start of the story. Nick Fury later states that Captain America introduced him to cannibalism, just before he shoots teenaged prostitute Jean Grey, and then himself.

Charles Xavier is president. He seldom leaves the White House. Nobody questions his authority. Most of the other mutants are confined to a prison, where Quicksilver has had all four of his limbs amputated and Cyclops has had his eyes gouged out. Xavier occasionally visits to rant at them. In one panel, Nightcrawler is shown chewing on his own tail.

Magneto's powers are uncontrollable. When his home-made limiter is broken by the police, he's killed in a hailstorm of metal.

Bruce Banner's accident turned him into a gigantic mass of tumours. It took him years to die. Rick Jones uses heroin to repress the memories.

The Kree sent an invasion fleet, but on the outskirts of the solar system they encountered the Silver Surfer's corpse. He had ripped himself open, desperate to feel something. The radiation from his corpse disrupted their shields, and their fleet was destroyed by nuclear missiles sent from Earth. The survivors, led by Captain Mar-Vell, live in a concentration camp on a nuclear test site. They're all dying of cancer.

Jonny Blaze is a motorcycle stunt performer. His biggest trick involves poring gasoline on his own head, and setting it on fire. When the narrator - the photojournalist Phil Sheldon - witnesses his act, it goes wrong; his motorcycle rolls into the desert with him still in the saddle, his head a burning skull.

Wolverine is dying of a bone disease, his skin sloughing off while he drinks himself insensible.

Sheldon tries to chronicle all this, trying to work out where the universe went wrong, but before he can get his photos and his notes back to the office he collapses and dies of the spider-plague - a hideous disease carried by Peter Parker, whose spider bite did nothing but make him patient zero for a pandemic.

It was written by Warren Ellis, who clearly was not having a good day.