Another update.
The big change was the death blow system. Heroes work the same as before, but enemies now get Death Armor instead of DBR. It's guaranteed death protection. You can break one per hit, with certain abilities that burn through it faster. It makes things harder, but less random. Items and abilities have been reworked accordingly. Generally, enemies with a lot of DBR now have a lot of Death Armor instead. I THINK it's a good change, but I'm not sure yet.
Focused Fault got a complete overhaul... again. Token theft is gone, which is good. Suppression has been reworked to punish positive tokens instead of crits. I don't think this is much better. DOT already rules this fight, and most of the game in general. Why do direct damage teams need to be punished for existing? Why do the devs have such a hateboner for direct damage? Blind immunity is gone, thank God. Seen tokens accrue faster, but there are now some ways to get rid of them, such as stealth or forcing a miss. There's a huge number of changes to this fight, too many to go into, but here's the bottom line: It's much easier to get him locked onto a single tank, but your defense best be immaculate, because his damage has been reverted to the previous 60 point crits. Poet ruled version 2 of this fight and really suffered from the changes. Now it's pretty much Vanguard, or Carcass with Stone Mount. Flagellant... well, he's great in every OTHER Mountain fight, but he just can't handle the big nukes on this one. Runaway also might be really good here now...
Mostly no hero changes, except that Occultist got buffed into the stratosphere. You know how I said that Wyrd would be a good heal if the threshold was changed from 33 to 50? The threshold was changed from 33 to 50, This is HUGE, and turns Occultist into a fairly competent healer. Curses now get 2 status stacks by default rather than 1, and the upgrade makes it strip buffs first. This makes Occultist much less upgrade intensive. I somewhat liked Ritualist before, contrary to popular opinion, but he's actually legit now. On top of that, Malediction got a massive buff, making it last longer and turning him into a good DOT support.
Also I forgot to mention the changes to infernal torches last time, mostly because I don't use them. But they do have a lot more variety now instead of just being the same with different numbers.
EDIT: One other thing I forgot. If a hero dies and you make it to the inn, you can now pick the replacement. This is excellent and makes a run less likely to be wasted due to a single death... if you can survive the cultist fight. Also, you can now change hero paths at the inn, for a price. I think this is mainly to allow you to select a path for your replacement hero, but it might has a few other edge case uses. Say, switching to Monarch just before the Mountain...