This Cursed Chest is exteremly rare, so expect to spend between 30 minutes and 1 hour in order to look for it.

There is only one possibility in the game, namely the ' The Cursed Peat' in Paths of the Drowned in act 5. The hard part is however to get a Cursed Chest which is capable to spawning over 350 mobs. It's extremely easy with a full four player group, and if you want to be 100 % sure to get it, invite at least one Demon Hunter to the group. If you lack strong AoE, use the achievement hunter or conquest communities to find a group to complete it.

These can clear this without any special gear, and probably only need around paragon level 200-300. Most classes with strong AoE builds are able to complete this solo, but UE and M6 Demons Hunters and wol monks are the easiest. These conquests can seem daunting, but are actually pretty easy to complete with the right setup. The conquest Curses! and Stars Align requires you to ' Kill 350 or more monsters in a Cursed Chest event on Torment X' in normal or hardcore mode, where Stars Align can be completed in hardcore only.

Diablo 3 conquests