WARNING: The following contains major spoilers for Doctor Doom #10 by Christopher Cantwell, Salvador Larroca, Guru-eFX, and VC's Cory Petit, on sale now.
Doctor Doom has long fancied himself as some sort of pariah savant turned savior of mankind, and he might not be that far off at this point. After being framed for an attack on Reed Richard's Antlion project on the moon, which caused a massive black hole to erupt, Doom had to clear his own name before being begged to solve the problem by the leaders of the free world. The opportunity to play the hero would inevitably lead Doom to a better world, one guided by a benevolent version of the mad tyrant himself. Instead of embracing this new and improved version of himself, Doom commits an act that solidifies his status as a truly heartless villain.
Doom's attempt to right a wrong he didn't commit quickly went awry, with the ruler of Latveria (and now Symkaria) second guessing himself after overthinking a kind gesture on the part of Reed Richards. Doctor Doom's own intervention of his already perfect plan set off a massive explosion, and when Doom awakens he finds himself in a majestic landscape staring up at a beautiful blue sky. Soon he is greet by a small group of soldiers, a medic, and a man he recognizes all too well. Standing before Doom is the most picturesque version of himself he's ever seen, one who is fast to offer a helping hand.
Doom tells his counterpart that he wants to learn from him, uncharacteristically in awe at the wonderous world that this version of himself has built. The two Dooms meet with Blue Marvel, who had also arrived on this Earth after diving into the singularity to escape the horrors of the black hole. Doom wonders if the world he comes from isn't the dark, mirror version of the one he has found himself in now, but his alternate assures him things don't have to be that way, and he leads a tour of how his Earth came to be a beacon of peace and prosperity. The technical and socioeconomic wonders of this Earth and their effect on Doom pales in comparison to the simple and infinitely happier life that the more altruistic version of himself leads. Gone are the trappings of an imperialistic monarch, and along with them the beliefs and ambitions of one.
Every improvement seems to hinge on the personal growth and betterment of Doom himself. Even while in possession of some of the most powerful artifacts in existence, this world's Doom remains calm and collected, while criticizing himself and his counterpart for any thoughts of expanding their own power or taking credit for where they've led humanity. The two speak in no uncertain terms that all of these incredible things can only be accomplished when Doom sets aside his pride, lust for power, and hatred. This pushes him too far, and he responds the best way he knows how, by murdering the man who dare speak to Doom as if they are equals.
It isn't unexpected, but it is surprising. Finally offered a real chance to do what he's sworn himself to and more, Doom chooses to eradicates that opportunity without blinking when it calls his ego onto question. Not just content with destroying the best version of himself, Doom annihilates everything even tangentially related to him, using the openly displayed Ultimate Nullifier to erase the entire universe from existence before sending himself and Blue Marvel home.
It was all but guaranteed that Doctor Doom's attempt to better himself, and by extension humanity, would fail before he could make any real headway, but this heel turn is still shocking. If nothing else, Doom has definitively answered the question of who he is, and who he will always be.