You could not be more wrong if you think Diablo 4 is over when you get to World Tier Four or even reach level 100. While defeating the Torment Capstone Dungeon and reaching level 100 are huge accomplishments, the Echo of Hatred dungeon is the final leap you must take to complete the game.
The Echo of Hatred dungeon is where the Echo of Lilith lies in wait. After you defeated the main story campaign, text boxes appeared on your screen that explained how Capstone Dungeons, Helltide events, and other endgame loops worked. There was also a box explaining that a harder version of Lilith was available once you reached a certain level. This version of Lilith is inside the Echo of Hatred dungeon, and if you’ve been looking for it, you can read my guide below to figure out exactly what it entails.