For Diablo 4's Season of the Infernal Hordes I created the hell infested Dungeons and Cellars used in the Seasons Story, as well as the Arena for the Core element of The Season; The Arena used for the Infernal Hordes gameplay. The Arena is located in a shard of Mephisto's Realm of Hatred, and features a fight against the Corrupted Council - a group of bosses fought in Travincal in Diablo 2.
I'd also like to credit Mina Kim for making the Hell Asset kit that I used to make this hellish construction!
Additional Shout outs to the Diablo Lighting team and to Antonio Watson - the Designer I worked closely with to make this space a reality.