There is something slightly strange about Diablo IV. The game is called Diablo, it has now spent several years expanding Sanctuary, introduced Lilith, brought Mephisto back to the centre of the story and even reached its final traditional expansion without ever doing the most obvious thing imaginable: making Diablo himself the main villain. Blizzard has now explained why. According to Diablo V Senior Art Director John Mueller, the Lord of Terror was simply too important to squeeze into another Diablo IV expansion. Or, as Mueller put it rather more efficiently: “Diablo’s very demanding.”
Speaking to Kotaku at BlizzCon 2026, Mueller explained that Diablo changes the scale of the story. Diablo IV began with Lilith and gradually developed a much more personal relationship between the player character, Lilith and Mephisto. Bringing Diablo into that framework later as another expansion villain would have meant attaching the franchise's defining antagonist to a story that had originally been built around somebody else.
Blizzard decided that was not enough.
Diablo Needed to Be the Centre, Not the Next Boss
Mueller's explanation is unusually revealing because the problem was apparently not that Blizzard lacked room for another expansion. The studio had freedom to decide whether the next big idea should become DLC, an expansion or an entirely new game. What changed the equation was Diablo himself.
Once Diablo became the character the developers wanted to build around, Mueller says the story needed to become bigger, bolder and more ambitious. He could not simply arrive after Lilith and Mephisto as the next name on Sanctuary's increasingly unfortunate appointment calendar.
That distinction helps explain why Blizzard decided to stop making traditional Diablo IV expansions after Lord of Hatred even though Diablo IV itself is not being abandoned. Seasonal content continues, new classes such as the Amazon are coming, and Blizzard has repeatedly said the live game will remain active. The numbered sequel exists because the next story required a different foundation.
Diablo V Begins After Diablo Has Already Won
The result is considerably more dramatic than simply putting Diablo at the end of another campaign.
As Blizzard revealed when Diablo V was announced for Spring 2029, the game begins roughly a century after Diablo IV in a Sanctuary where the Lord of Terror has already won. Humanity's heroes failed. Westmarch has fallen. Civilization survives in fragments, and the player begins the game inside a world that Diablo has already reshaped rather than one waiting for him to eventually emerge from a portal during Act VI.
Blizzard's official description is almost aggressively simple: Sanctuary has fallen. Diablo won.
That premise immediately gives the villain something Diablo has surprisingly rarely received across the series: time.
We normally meet Diablo while trying to stop a plan. Diablo V starts after the plan worked.
A Sequel Let Blizzard Change the Framework
Mueller also points to a more practical reason for making a sequel. The team wanted to change the actual framework of the game rather than continue extending Diablo IV's structure. That freedom is visible in almost everything Blizzard has shown so far.
Traditional towns and safe hubs are largely gone. Instead, players travel with a caravan of survivors. Dungeons remain procedurally generated, but now the overworld itself can change as well. Dread Commanders reshape regions through “terror-forming”, affecting terrain, monsters and landmarks. Blizzard is rethinking level scaling, itemization, inventory and progression while simultaneously promising more classes than any previous Diablo launch.
Those are not small additions to an existing expansion framework.
They are the sort of changes that become much easier when the development team is allowed to call the project Diablo V and rebuild around them.
The Story Is Supposed to Be More Personal Too
There is another part of Mueller's explanation that is easy to overlook. He is proud of the way Diablo IV's storytelling became increasingly personal, particularly the relationship between the player character and major figures such as Lilith and Mephisto. Diablo V intends to take that idea considerably further.
Mueller says the characters should matter like the cast of a favourite television show. The caravan is central to that philosophy because its inhabitants travel with you instead of waiting permanently in town with punctuation floating above their heads.
That fits Blizzard's slightly terrifying internal ambition of creating the “best campaign ever” with Diablo V. It is not a claim that the unfinished game has already achieved that. It is the target the team has set for itself.
And again, Diablo is the centre of it.
Diablo IV Was Never Really His Story
Looking backward, the decision makes more sense than it initially appears.
Diablo IV belonged to Lilith from its opening cinematic. Even when Mephisto moved into the foreground, the story remained rooted in decisions, relationships and consequences established around Lilith's return. Dropping Diablo into the final expansion simply because the title says Diablo would have risked making the franchise's biggest villain feel like post-launch content.
Instead, Blizzard has given him an entire game whose opening situation exists because of him.
That may also explain why the sequel is willing to jump so far forward in time. A century gives Blizzard room to let Diablo's victory become history rather than a temporary cliffhanger. Towns disappear. Cultures change. The landscape itself bears the consequences. Players do not merely hear that Diablo is powerful because an NPC tells them so.
They begin inside the world he broke.
Diablo Was Apparently Too Big for DLC
There is something wonderfully appropriate about all of this.
Diablo IV could have ended by opening another portal, introducing the Lord of Terror and giving players a new raid-sized problem to solve. It would have been easy to understand and probably easy to market.
Blizzard instead decided the character demanded a new game, a different world structure and another multi-year development cycle.
Whether that ambition produces a better Diablo will not be clear until 2029. Diablo V is still early enough that Blizzard is openly showing systems it expects to change, and the game was revealed this early specifically so more player feedback can shape development.
But at least we now know why Diablo never arrived as Diablo IV's final expansion boss.
Apparently the Lord of Terror does not do supporting roles.
