WARNING: The following contains spoilers for Old Man Quill #12, by Ethan Sacks, Robert Gill, Andres Mossa, VC's Joe Caramagna, on sale now.
There are few beings in the Marvel Universe as overwhelmingly powerful as Galactus. The planet-eating cosmic being is usually held up as one of the most fearsome figures to go up against. There are few people who can claim to stand a chance against him, let alone to actually defeating him. Now, however, an unlikely human hero can join that shortlist.
In Old Man Quill #12 Peter Quill, the last of the Guardians of the Galaxy, was able to think of a pretty clever (and very brutal) way to actually bring down Galactus once and for all and save the Earth.
In the dark future of the Old Man universe, things have somehow gotten so bad that Galactus' return isn't even the most pressing concern -- at least initially. With almost every hero long dead (and even the villains who took control in their stead slowly dying off), there's no one left to stop the cosmic being from consuming Earth -- except for Peter Quill.
But without the Ultimate Nullifier, it initially seems like a hopeless endeavor. Captured by Doctor Doom and Madam Masque, Quill isn't able to successfully warn them of the danger coming right for them. Yet, Quill has another cosmic level ace up his sleeve. As he's captured, he is able to use the powers of the gem to hide away the Time Stone on one of Madam Masque's henchmen, preventing it from being detected.
When the resistance arrives and saves Quill, the guard is among the casualties. Quill takes the Stone back. Confronting Galactus, Quill loads a sliver of the Time Stone into his revolver and fires it straight up. He lands the shot directly in the center of Galactus' brain. While it initially has no effect due to Galactus' connection to the power cosmic, Galactus soon collapses in a giant heap on the ground. It turns out that the Time Stone was embedded in Galactus' brain and took parts of it with it when it blasted through time. This left Galactus functionally braindead and in a coma, preventing him from destroying the Earth -- or doing anything really.
Disregarding any future problems that come about whenever a celestial figure like Galactus is contained, this seems like a massive win for the Old Man universe. Considering how hard things have been for the survivors of the world, it's no wonder that they've been struggling to get back on their feet. Now, the heroes have proven that even when Earth is on its last legs, it's still strong enough to take on cosmic threats if need be.
It's a genuinely creative way to bring down Galactus, leaving him technically alive but incapacitating him for what's likely to be forever. It's doubtful anyone would even attempt to reverse what happened to the lobotomized Galactus, or would have any real reason to do so. It's a brutal tactic but one that at least brings him down once and for all.
This also gives Peter Quill, portrayed throughout the series as a washout drunk and the worst member of the Guardians of the Galaxy ever, a major victory. It's no wonder that the issue ends with Quill recruiting a new Guardians of the Galaxy to target the remnants of the Church of Universal Truth. The group that had revered Galactus as their God left a path of destruction in their wake and was responsible for the deaths of his former teammates. Quill will be able to reenter the fray as the one responsible for taking down Galactus, which will carry a lot of weight through the universe.