Brief Synopsis
Null’s hatred of the gods spawns Demon Kings through a process very similar to how Ganondorf spawned Calamity Ganon, and different Demon Kings like Demise, Malladus, and Ganondorf are like different incarnations of Calamity Ganon but with Null as their source.
How it Happened
Null exists in a physical place deep beneath the surface of Hyrule, the World of Light. Due to the actions of the Golden Goddesses, seen in Echoes of Wisdom, Null harbours an intense hatred towards them.
This hatred of the gods would radiate from Null and eventually concentrate into Demise who would go on to oppose the gods. When Demise is eventually defeated, the influence of the Demon Tribe wanes until waxing again and forming a new “Calamity” in the form of Ganondorf. And just as a particular Ganondorf is defeated, a new Ganondorf (or a different form of Demon King) would appear to replace it.
This is why defeating a Demon King doesn't actually stop the Demon Tribe itself or prevent the reappearance of a Demon King. The underlying force of hatred behind the Demon Tribe comes from an external source: Null.
Exhibit 1 - Ganondorf and Calamity Ganon
Let’s more closely examine the relationship between the Wild Era Ganondorf and Calamity Ganon so we can understand Null and Demise.
In the distant past, Ganondorf opposed Rauru and was sealed beneath the earth. Rauru’s seal on Ganondorf was imperfect and, despite the bolstering by later generations, his Malice would emanate from his body. After enough time, the Malice would physically concentrate into Calamity Ganon. Calamity Ganon should not be thought of as a conscious extension of Ganondorf. Rather, Calamity Ganon is a physical manifestation of Ganondorf’s malicious will.
And when Calamity Ganon is defeated, that particular entity truly is gone. However, the energy that spawned Calamity Ganon persists and a new Calamity Ganon will eventually be created.
In a way very similar to how Ganondorf spawns Calamity Ganon, Null would spontaneously form Demise. The sealed body of Ganondorf radiates Malice which concentrates into the entity Calamity Ganon given enough time, which is a distinct entity from the source Ganondorf and seems to reflect the unconscious will of Ganondorf.
Null would likewise radiate a malicious energy that would concentrate into the first demon, Demise. Like Calamity Ganon, Demise is not a mere extension of Null but rather is a distinct entity reflecting the unconscious will of Null. This unconscious will of Null is that of an intense hatred of the gods and a desire to escape its seal. Embodying this will, Demise would oppose the gods and ultimately be destroyed by Link. However, just like Calamity Ganon, destroying Demise did not prevent new incarnations of Null’s hatred from spawning. That hatred would incarnate later as Ganondorf.
Exhibit 2 - Age of Calamity
In Breath of the Wild, Calamity Ganon takes several shapes including a gaseous Malice form (the form that circles around Hyrule Castle and is sealed by Zelda), a boarlike, pure-Malice form (the final phase of the boss fight), and a physical Malice-Sheikah hybrid form (the body inside the cocoon in Hyrule Castle). Part of Calamity Ganon’s goal was to create a physical body for itself, however it was forced to use an incomplete body as Link forced the encounter.
In Age of Calamity, Calamity Ganon is able to obtain a body for itself by absorbing Astor’s body into its own. The resulting form is a humanoid Ganondorf-like creature with the title “Hatred and Malice Incarnate”. We can assume based on previous scenarios of Demon Kings attempting to occupy the body of a “bad” host (bad in the sense that a being possessing great amounts of Force, like Princess Zelda, are typically the “desired” host) that even this form of Calamity Ganon is still imperfect.
However, what all of this demonstrates is that a Calamity is not a powerful, mindless, floating gas. It is a being that strives to “condense” itself into a physical, sentient form.
This more complete form of Calamity Ganon, closer to what Breath of the Wild’s variant was seeking to become, is described in a way that perfectly encapsulates what Demise was: Hatred and malice incarnate.
Exhibit 3 - The Curse of the Demon Tribe
The Curse of the Demon Tribe has generally been understood in one of two ways:
1. It is a curse deliberately placed by Demise during the final encounter with Link that is the reason Ganondorf later came to exist as his successor.
2. It is a description of an inevitable law of reality. Every time you destroy a Demon King, it allows for the eventual creation of a new one.
There is generally not a consensus on this debate, however I’ve typically accepted the second description as a better description.
Nonetheless, what is notable though is the way that the Curse of the Demon Tribe is expressed in a way that aligns with the notion that Demon Kings are “Calamities” of Null.
Let us look at Demise’s dialogue for context:
“Though this is not the end. My hate…never perishes. It is born anew in a cycle with no end! I will rise again! Those like you… Those who share the blood of the goddess and the spirit of the hero… They are eternally bound to this curse. An incarnation of my hatred shall ever follow your kind, dooming them to wander a blood-soaked sea of darkness for all time!” - Demise
Think back again to Calamity Ganon and Ganondorf. Suppose Calamity Ganon was capable of speech and spoke to Link before its defeat. Knowing what we know about Calamity Ganon, where it comes from, and how it’s created, it would be entirely appropriate and accurate for Calamity Ganon to state the same thing to Link. Just like Demise claims, Calamity Ganon’s hatred never perishes because it comes from a persistent external source: Ganondorf. It is indeed born anew in a cycle because Ganondorf remains secretly sealed away, able to spawn new Calamity Ganons in perpetuity, until defeated in Tears of the Kingdom. The only beings generally capable of stopping Calamity Ganon are the hero and the princess meaning these three beings are locked in a near-eternal, cyclical conflict.
If Demise is part of an eternal, cyclical conflict in which new incarnations of this force of hatred spawn new Demon Kings, then we must ask ourselves: If Demise is like Calamity Ganon, and even Ganondorf himself is like Calamity Ganon, who is the “Wild Era Ganondorf” to Demise?
Exhibit 4 - Wild Era Ganondorf’s Design
Ganondorf in Tears of the Kingdom is particularly notable in this discussion as he is the first new Ganondorf since the introduction of Demise in Skyward Sword. As we already had good indication of, Ganondorf’s design further solidified that he is a successor of Demise and an incarnation of that same hatred that Demise was an incarnation of.
Normally, the conclusion that would be drawn is that Ganondorf resembles Demise because Ganondorf is an incarnation of Demise’s hatred. However, it may be more appropriate to conclude that Demise and Ganondorf resemble each other because they are both incarnations, or Calamities, of the same source: Null.
Exhibit 5 - Malladus’s Design
A particularly curious Demon King is Malladus who hails from New Hyrule. Not much is known about Malladus other than he was sealed in ancient times by the “spirits of good,” but what is notable is despite being completely unrelated to Ganondorf, it still resembles him through his boar-like form.
He does have orange hair just like Ganondorf, but that is more likely tied to Malladus taking Chancellor Cole’s body. But the boar form isn’t explained by Cole and is an interesting coincidence to consider when thinking about what connects Ganon and Malladus.
However, if we think of Malladus as a Calamity of Null just as Demise and Ganon are, this resemblance makes sense as all three entities are spawns of the same underlying energy of hatred from Null. There is a shared design language to the Demon King that can be intuited by comparing Demise, Malladus, and all the forms of Ganon.
Why does Malladus, a being with no connection to Ganon, turn into the form of a boar just as Ganon has done multiple times? This is because both Ganon and Malladus are the same kind of entities; and Ganondorf resembles Demise because both are the same kind of entities as well.
These Demon King appearances have been consistent enough that it would be reasonable to assume even a brand new Demon King would still resemble Ganon even if it were not related to him.
Exhibit 6 - Malladus’s Final Fight
This section was added after I published this theory (mostly because I am fairly unfamiliar with Spirit Tracks compared to other games), but there is a notable piece of dialogue from the final fight after you strip Malladus of Zelda's body and he is forced to manifest through Cole's.
It has been a point of contention while comparing the motivations of Null with that of the Demon Tribe that while Null seeks destruction of the world, the Demon Tribe seeks to dominate the world as well. However, we have also seen what a demon is willing to do when backed against the wall and that is to destroy the world itself.
One Additional Point
I think something that must be addressed here is this: What is the point of any of this when we can just assume Demise has always existed and is the true source of beings like Ganondorf and Malladus?
We have received new lore since Skyward Sword, and with that new lore we have come to understand the true nature of the creation of the world itself. We have seen nearly the very beginning of everything.
In the beginning, there was Null and there were the Golden Goddesses. Null desired to consume all matter and the Golden Goddesses did not appreciate this behavior and so they sealed Null away with the world. The world only exists because the Golden Goddesses sealed Null.
With this new, expanded origin story, fans must integrate it into their understanding of the series as a whole.
Is it just a coincidence that the two most ancient, yet apparently unrelated, villains share a core hatred of the gods? Is the emergence of the Demon Tribe truly independent of Null? If Null and Demise are related, what exactly would that relation be?
The line of thinking in this theory is my attempt to establish a connection between Null and Demise in a way that conforms with the established lore and storytelling patterns of the series.
Conclusion
The Demon King is not merely a single person, a recurring soul, or a localized curse; it is a cosmic symptom. Just as Calamity Ganon was the physical eruption of a sealed Ganondorf's lingering malice, every Demon King throughout history including Demise, Ganondorf, and Malladus, is simply a Calamity of Null. It is the physical eruption of the lingering malice of a primordial entity trapped within the World of Light.
To understand how the history of Hyrule unfolds under this paradigm, we can trace a timeline of Null’s influence across the eras:
1. The Era of Creation & Sealing: The Golden Goddesses form the World of Light as a prison around Null. Deep beneath the earth, Null’s intense, festering hatred of the gods begins to radiate into the world.
2. The Era of Hylia (The First Calamity): Over eons, this malice condenses into a physical, sentient form: Demise, the very first Calamity of Null. Driven by Null's instinctual grudge, Demise breaches the surface with his demon army to destroy the Goddess’s realm and claim the Triforce.
3. The Era of Skyward Sword: Link defeats Demise, destroying his physical vessel. However, because Null remains trapped and active beneath the earth, the true source of that hatred remains.
4. The Era of Successors: As ages pass, the malice radiating from Null continues to find new hosts and form new Calamities. Mortal men with wicked hearts like Ganondorf, or ancient evil spirits like Malladus, draw upon this same primordial wellspring of a malicious Force. In doing so, they inherit Null's intrinsic, unending hatred of the gods.
5. The Era of the Wild: Sealed beneath Hyrule Castle, Ganondorf inadvertently replicates Null’s phenomenon on a smaller scale: his trapped body leaks Malice to spawn Calamity Ganon, creating a Calamity of a Calamity.