First of all, I am sure you all recall this very controversial scan from the Devil May Cry 3 manga's official translation, which mentions Heaven and Earth being at war, the link between Heaven and Earth being rendered unstable and the Demon World being spawned from said link, and slaughtering many humans as a result.
Now, this had always struck me as a very weird DMC legend. Not only is something like this never alluded to in the series ever again, but it heavily contradicts several plot points, such as the existence of a literal, separate "Heaven" with angels, which Itsuno himself has stated not to exist on DMC, it contradicts the omniscient narrator's version of the events, which states that the Demon World came before the Human World and, in fact, was responsible for spawning the Human World, and it also mentions some sort of war on Heaven that is never carried forward.
So I decided to take a look at the Devil Lair's scanlation. Devil Lair has its ups and downs, but their version of this page is significantly different from the Official Translation, and it actually fits in rather nicely in with the lore of the franchise, and doesn't actually contradict any plot points established on any other medium of the series:
After downloading the Raw Japanese manga, I set out to ask a native Japanese speaker on this wiki of which one of these two were more accurate, or if either of them were in fact, accurate at all. To my non-surprise,
I was told that the Devil's Lair version was the more accurate of the two in this particular page. Credits to Shiro for confirming this.
Here, the translators note that "Heaven" referred to in the page is just another word for the Demon World. So any contradictions about a literal heaven with angels arising from this page are dealt with right away.
Now, the scan states that there was a lot of pandemonium and chaos spilling between the border of the Human World and the Demon World, and that the Earth was torn apart with great rents whenever "the wrath of heaven poured down on them", resulting in many lives being lost. Many DMC fans believe that this page is talking about Mundus's invasion on the Human World. But is it?
Notice the fact that the scan specifies those events took place
during the birth of Heaven and Earth. Let's revisit the prologue/introduction for the Devil May Cry 3 manga, shall we?
And thus we arrive on the conclusion that it's not talking about the invasion by Mundus's armies - this tale is in fact expanding on what was stated by the narrator in the prologue of the manga, before the Human World and the Demon World were separated, the first chronological event in the series. So, going by this scan, back when these two worlds were still one, there was great pandemonium and chaos caused by distortions and instabilities spilling from the side of the Demon World/Heaven to the Earth.
This brings me to the very next page after this one. This time, we swap back to the Official Translation,
which was confirmed by professional translators over Reddit to be more accurate on this particular page.
The one introducing the black-horned demon. We are told that, at the time heaven and earth were rent asunder (ie.
divided in two), this demon emerged from the darkness, and hammered this spike into the Earth so that heaven and earth "would never again be split apart."
Now, notice that, in both translations, this demon is referred to as a "Demon God'. Only four demons were ever awarded such a title on the series; Argosax, Mundus, Urizen and the unnamed demon king killed by Mundus - and all four of them happened to share the trait of being Demon Kings/Demonic Emperors.
Now, recall what was stated about Pluto on DMC1:
- "Pluto shall come on the promised date and separate heaven and earth. One with black wings of treachery shall come and stand in Pluto's way."
With all of this together - I conclude that Pluto is, in fact, the black-horned Demon God with a spear, the ruler of the Underworld at the time. Back when the two worlds were one, he emerged from the Demon World and used this spear to separate both worlds -just as stated on the prologue. We know this is not referring to Sparda because those events happened even before Mundus's birth altogether.
Since those scans are the only times Heaven is mentioned in the series, it makes sense that they'd all fit in together.