New to the Marvel Universe is the Soulsplitter Stone, a potent gem with even more sinister abilities than some Infinity Stones. In Marvel Comics' All-Out Avengers #2, Doctor Doom uses the new stone to split himself into two distinct parts: his most heroic and wicked selves. Unfortunately, without assistance from the other Doom, not even the Avengers are powerful enough to defeat the bad guy.
The Marvel Universe's most potent objects, both individually and collectively, are the Infinity Stones. The owner of an Infinity Stone has the power to alter time, space, reality, and more with only one stone. The Infinity Gauntlet and the Infinity Stones together give the wielder the power to rewrite reality, space, and time in their own image, just like Thanos did when he had all six of the Infinity Stones. The Soulsplitter Stone is a new stone that Marvel is introducing. Although it lacks the Infinity Stones' power, due to its abilities, it may be the darkest stone in the universe.
The Avengers are headed by Doctor Doom in All-Out Avengers #2 by Derek Landy, Greg Land, Jay Leisten, Frank D'Armata, and VC's Cory Petit. After being split in two by the new Soulsplitter Stone, Doctor Doom has evolved into a Mjolnir-wielding hero. The non-Infinity Stone spawns two distinct versions of Doom, including the darkest Doom that the valiant Victor Von Doom fights. The evil Doctor Doom eliminates the Avengers one by one, coming close to killing them. But the sacrifice of their newest ally helps the heroes win.
The heroically inclined half of the split character ends up making the ultimate sacrifice, shattering the stone and making the antagonist whole once again, while the Avengers fret about shattering the Soulsplitter Stone and bringing back the real Doctor Doom. The Soulsplitter Stone is destroyed, but it rapidly becomes clear that it might have been just as destructive as an Infinity Stone because it could have unleashed the worst and most valiant aspects of anyone it affected. If the stone ended up in the wrong hands, it would be fatal if a hero, like the Hulk, was split in half.
Whether the Soulsplitter Stone will ever surface in another Marvel Comics narrative is not fully certain. However, even if it just makes one appearance, the gem has the ability to unleash the worst form of everyone it affects, making it much more sinister than some of the Infinity Stones. The Avengers came very close to being slain in this instance by the darkest Doctor Doom, but it might have been far worse for Earth's Mightiest Heroes. Marvel Comics' All-Out Avengers #2 is currently available in comic book retailers.