Season of Hell’s Legacy spreads two more kinds of waking nightmares across Diablo IV’s overworld, Owen Leach, Lead Encounter Designer, explained at the Diablo IV: What’s Next panel at BlizzCon 2026. Like the Prime Evil questline versions, each recreates a key moment from an earlier Diablo game.
The first is what Leach called standard waking nightmares: about 10 overworld dungeons that act like regular dungeons, which you walk into and can use nightmare dungeon keys on. In Tal Rasha’s Tomb from Diablo II you assemble the staff, place it in the pedestal, and blow open the door. The Scouring of Caldeum, the end of Diablo III’s Act II, has you fight beside Leah through the city and into the palace to confront Emperor Hakan, who turns out to be Belial. The Den of Evil from Diablo II and Halls of the Blind from Diablo I were also shown.
The second is pop-up waking nightmares, tested as the challenge rifts on the public test realm. They are injected into overworld combat: during a Helltide, for example, a portal opens onto a wave event, a boss fight, or a short quest. The examples were Pandemonium from Diablo III with Malthael’s lieutenants outside the soul prison, Na-Krul from Diablo: Hellfire, and Zaka the Abyssal Worm from Diablo Immortal’s Realm of Damnation.
Leach put the count at about 15 pop-ups and about 30 waking nightmares in total. Names were said on stage, not shown on screen, and no full list was given.