I loved that Savagery build when Ultos’ set added an extra target, which lasted for all of one patch (1.1.9.3, if you’re curious). It was just super fast and simple and fun.
I started leveling this Blazerush build using Barthollem’s Warmaul and I can confirm that it can and will proc multiple Upheavals in a group.
Ascended Diadem gives 6% OA to Stormcaller’s Pact so it might be possible to create something similar to the old Ultos’ with the new attack radius on Barthollem’s, but as @Gnomish_Inquisition said, it will take a ton of MIs. I started a Grimtools (didn’t finish cuz it was so fantastical) and at least the weapon, head, chest, and amulet were MIs. And the shoulders, pants, rings and belt should probably be MIs, too. But possible!