The Existing Labyrinth/Trials of Ascendancy
We've changed the existing Trials of Ascendancy so that your progress is shared between all characters in the league. If you complete a Trial, then you won't need to later complete that one on a subsequent character in that league.
We've solved a lot of problems with the layout of the Labyrinth and fixed a myriad of small issues with most rooms. We have also improved the rewards at the end of side content in the Labyrinth, to make those areas more enticing.
There's also a new gauntlet type where you have to move a payload object on rails through an area.
Endgame Trials of Ascendancy
There are a new set of six Trials that can be occasionally found in maps. They all occur in lower maps, and it is intentional that it takes some time to complete the set of all six. The Trials are longer and harder than the ones found in the regular game and aren't static. They are designed for replayability and feature more complex random sections. When you encounter a Trial in a map, it's a sub-area like a master mission would be. These Trials introduce the new trap type - Sentinel Traps.
Sentinel Traps are stationary traps that can be suppressed by dealing damage to them. After being damaged, they deactivate for a few seconds. They'll reactivate automatically a little while later. While active, their payloads can include various types of elemental damage and negative effects such as hurting you if you use a movement skill nearby. You'll want to keep them suppressed as much as possible while solving the Trials they are in.
Endgame Labyrinth
You can only enter the Endgame Labyrinth after you have completed all six Endgame Trials of Ascendancy in that league. You'll need a special item to get into the Endgame Labyrinth, but one of these drops at the end of each Trial (even if you haven't completed the entire set yet). By the time you gain access to the Endgame Labyrinth, you'll be able to run it at least six times. After that point, you'll need to either complete more Trials to get more entrances, or trade for people who have incidentally completed the trials while playing maps.
Note that while the item that allows access to the Endgame Labyrinth is used in a Map Device, it technically isn't a map, so Zana mods and sacrifice fragments don't affect it. It is absolutely not the same thing as the new Plaza Map base type that we're also adding. Because the endgame Labyrinth is not a map, the monsters in it do not drop maps (higher than Tier 1 at least). However, you can get higher maps out as a reward if you pick the right chest at the end.
You can play the Endgame Labyrinth with a party. Six portals are opened, like with maps. The entrance is an "airlock" like on its other difficulties, so the full party must enter together. There are a few new surprises that you'll encounter when playing this Labyrinth. We'll be watching Twitch with interest ;-)
Rewards
As the Endgame Labyrinth is the fourth Labyrinth you'll play through, there are a fourth tier of rewards. Completing it unlocks two additional Ascendancy points (for a total of eight). You'll also be able to imbue an item with a fourth-tier Enchantment. There's also a fourth jewel reward for the fastest player to complete the Endgame Labyrinth in each league each day.
In addition, the treasure chests at the end of the Labyrinth are higher level than the Merciless ones and some of them can drop higher-tier maps.