In Grim Dawn, there’s a DLC called Crucible (2016), you just have to kill every wave, each one is more difficult than before. As I know, it doesn’t have limit. You get the reward until you lose. I think is can be very good for Diablo, when doing ND and hit surviving events, those are the only thing is fun in that type of content.
Unique events for Hell tide, like summon a boss more stronger than Kixxarth. Every 10 Aberrant Cinder, increase the level (90 lvl base), and every 50 it get an elite enchant. 200 cap. If you hit the cap and kill the boss, you will get the half of cinders and loot of tortured gift.
Share other form of end-game!