Project Hades would have been Diablo's take on Dark Souls, described as a over-shoulder third-person dungeon crawler. Unfortunately, the project never manifested and was cancelled due to or because of a rough development cycle.
While exacts of the project never manifested, it's an interesting idea nonetheless. Soulslikes have never quite hit the pedigree offered by FromSoftware, but Diablo is such an established franchise that the possibility of a lovechild between it and Dark Souls can definitely perk the ears.
It's possible some take on this is in the works at Blizzard, that's if it didn't completely abandon the idea, but that is just speculation and is admittedly unlikely. Trying to guess where it might have went, it's possible that Diablo 4's classes (the Barbarian, the Druid, and the Sorceress) could be manifested in such a game.
This would likely combine Dark Souls-style gameplay and class approach, with cheap Diablo 4 Gold providing the overall flavor. It's not hard to imagine approaching of one Dark Souls' notoriously difficult bosses, with the melee power of Diablo's Barbarian class, a unique tank build for the Druid, or the magical might of the Sorceress.
