The Second Galactus Engine was once Galactus' counterpart from The Cancerverse until The Many-Angled Ones of the outer dark took him apart, amplified the power within his corpse and bio-engineered an apocalyptic mechanism, an engine of cosmic annihilation unlike anything the Multiverse had seen before.When The Many-Angled Ones, from behind the scenes, learned that Earth-616's Galactus had brought Tenebrous, Aegis and The Prime Celestial Host with him to The Fault to keep them from achieving their ultimate goal.
That goal was, of course, conquer the mainstream Marvel Universe and then rewrite the base code of The Multiverse, thus allowing them to turn every reality they had yet to conquer into an extension of The Cancerverse, so in response to Galactus' counterattack The Many-Angled Ones sent his counterpart, The Galactus Engine, through.
When it made its grand entrance, Nova, Quasar and The Silver Surfer were shocked to discover that the foul abomination dwarfed every single cosmic being stationed at The Fault in size, making them look like ants much in the same way Nova, Quasar and The Silver Surfer were to the cosmic beings.
A painful death awaits all who defy The Galactus Engine.When The Galactus Engine finally broke through The Fault; all of the cosmic beings standing before it moved aside in order to avoid being hit with the exception of Galactus himself, who decided to face his twisted counterpart head-on.
Shortly upon arrival, The Galactus Engine did not seem to be attacking anything at all but in reality was waging a fierce war with the Abstracts on a higher plane of existence far beyond the ken of mortal men.
However, when it overwhelmed Aegis and managed to kill her, the end result was viewed on our plane of existence in the form of a massive xenomorphic entity tearing its way out of her body. It was not long before her allies as well as the mortal armies of 616 began to drop like flies.
Though it was not seen firsthand, Quasar remarked that The Galactus Engine had actually begun forcing the cosmic entities and their mortal allies into retreating, though because of all the confusion and chaos going on at the front lines it was impossible to tell just how many of the cosmic beings had actually fled from the front lines.
Following the return of Nova's strike-force from their mission to rescue Major Victory and Namorita, Queen Medusa explained to them that The Galactus Engine had proved to be the most powerful and monstrous threat on the battlefield so far, which had wiped out or forced into retreating all but five of the High Abstracts that had come to assist the lesser beings in fending off the Cancerverse's assault vanguard earlier on.
Galactus and his crew struggle to hold his monstrous counterpart at bay.The five remaining High Abstracts; Galactus, Arishem the Judge and three nameless Celestials who, despite focusing every iota of their vast power into combating The Galactus Engine, were noted in the reports Medusa received from the front lines as being barely able to hold The Galactus Engine back.
To make things even worse, other reports had confirmed that there were larger, more powerful creatures (possibly The Many-Angled Ones themselves) coming through The Fault from behind The Galactus Engine and the two parsec-wide assault vanguard flanking it.
Eventually, Arishem and the other three Celestials were overwhelmed and possibly destroyed by The Galactus Engine, leaving only Galactus to fight back against his monstrous counterpart. But as their fight progressed, The Galactus Engine unleashed hundreds of robotic tendrils from its mouth and began wrapping them around Galactus' arms.
As it began to pull him downward, Galactus found himself being assisted by the lesser beings fighting in this war, who had all decided that The Galactus Engine should be everyone's priority now that the other High Abstracts had been killed. But even with the promise of what little aid they could provide, the outcome of this fight still looked grim.
Then, when all hope seemed lost, Mistress Death obliterated The Cancerverse and caused The Fault to collapse in on itself, creating a back-rip that pulled The Galactus Engine and any portions of the assault vanguard that hadn't turned to dust down into oblivion. With Mistress Death's aid Earth-616 had come out of the war victorious, but the cost of that victory had been great.
Nightmare's EndThe Galactus Engine had left every species that confronted it, including The Celestials, in ruins. The Celestials themselves now lacked their primary Judge thus leaving Arishem's position along with countless others to now be filled.
As for the "lesser" races...millions upon millions of people, people that were loved and cared for deeply by many, had been exterminated in the blink of an eye by forces they could not understand or imagine.
Though it is gone, The Galactus Engine's dark and twisted legacy along with records of its actions will be remembered by every generation until the end of time and space and light and life.