Owen Leach, Lead Encounter Designer on Diablo, said the team made 20 new bosses and 25 new monsters for Season of Hell’s Legacy during the Diablo IV: What’s Next panel at BlizzCon 2026. The bosses come from earlier Diablo games. “It’s another thing to fight the monsters from those old games,” Leach said.
He named Blood Raven, Queen Araneae from Diablo III, Archbishop Lazarus, and the Summoner. Nihlathak from Diablo II appeared in footage labeled Legacy Content: Returning Bosses, and Leach said players take him down “for what he did to Anya.” The footage also showed the Maggot Lair and Coldworm the Burrower, and Leach said lightning enchanted scarabs and fly swarms that steal your resources are in. Boss names were said on stage, not shown.
Friendly NPCs return as well. Footage labeled Returning Characters set old isometric scenes beside the Diablo IV versions of Pepin, the healer from Diablo I, and Griswold. Leach also named Tyrael from Diablo II, in angelic form, as “my favorite character by, like, a wide margin.”
The team rebuilt the models but imported the old voice lines and music. “So when you hear Tyrael, he’ll talk in Tyrael’s voice,” Leach said. He recalled playing Diablo I at a friend’s house in 1996, “getting the Butcher stuck in the staircase because we can’t beat him otherwise.” The panel then played a clip of the line “Not even death can save you from me” without naming its source. Only six of the 20 bosses were named.