Well, unless the guy in the last link is off, the only mystery is why they left their tent in a hurry.

If that is the case, then I doubt anyone will ever know.  Could be a million reasons, I suppose.  I don't see any evidence available that is conducive to speculation one way or another, so while I could speculate and come up with some plausible scenario, I don't see much point.

Yes, lack of information indeed. However I can't find a reasonable explanation why they left the tent in those conditions and why they haven't returned imediatly....

This happens frequently near Portland, Oregon where I live.  Thousands of people climb to the top of Mt Hood every year.  It is a volcano that is currently inactive.

It isn't all that tall, and I guess it isn't that difficult of a climb.  But it is notorious for quickly changing weather.  Even people who have climbed the mountain many times before have gotten into trouble.

One group of guys were all experienced climbers, had climbed Mt Hood many times before, and the weather prediction was for a storm in a few days.  Didn't take locators - gps devices which you can check out at the ski resort.  The storm arrived early, one of them fell.  So they put him in a snow cave they built and the other two tried to climb down for help.  They found the one in the cave frozen to death, they have still not found the other two.  Since it is a couple of years later, people figure one day they may find pieces of them scattered by the local coyotes.

The two guys should have known better than to keep trying to walk down.  If they had stayed in the snow cave with everyone bundled up together, they might have had a remote chance of not freezing to death.  Smart people make stupid mistakes all the time.

I don't think there really is that much of a mystery. It seems clear to me that some died from the fall and others from exposure. The only question is why they left the tent unprepared. It very well could have been a bear, there are brown bears in Northern Ural. Given the amount of time between when they were supposed to be back from the trip and the search started, it is very likely that any bear tracks would have been covered. There are also wolves in Ural but I think it is unlikely that a group of experienced skiers would be scared of a wolf.

Other possible explanations would be drugs that caused either hallucinations or paranoia. Also, there is always the possibility that one member of the party went psycho and was trying to kill the others. For those of you who have never been stuck in a tent for an extended period of time because of bad weather let me assure you that it can be very difficult to handle mentally. Even when you are stuck with someone you like a lot. If they were confined to the tent for several days it is not unreasonable to believe that some sort of conflict started between them and it escalated leading to either someone chasing someone else out or perhaps just going batshit crazy and running out with the other members of the team running after them trying to catch them to stop them from hurting themselves.

There are a lot of ways to die in remote locations so I am never really surprised when people do die. Even the most experienced outdoorsmen can find themselves in very deadly situations and do stupid things.

That is a valid point as well. These people died in a mysterious manner and were autopsied. So where are the toxicology reports? Without those, we cannot know just what might have been in their bllod streams that could have led to some seriously batshit behavior.

One possibility would be lead poisoning. This happens to hunters often enough to be statistically significant. There are two ways that this can occur.

First is that when bullets strike bone, they can shatter and spread tiny pieces of lead through the meat that are not easily seen and removed.

Second is that when bullets hit major joints such as shoulders, knees or hips, enough lead can be chemically absorbed into the animal's blood stream before it dies as to make the meat toxic.

Now, one of the linked sites tries to refute the idea that the party may have had guns because one of the pictures may have been from a different party. Umm, whatever. These were people with an experienced guide who knew where they were headed. What manner of idiot heads into bear country without guns?

Then add the fact that they were caching supplies for the return trip. If you have to do that, it makes a certain amount of sense to chow down on some animal that you may have shot.

Another possibility would be vitamin A poisoning. It is fairly well documented that arctic predators will tend to have increased levels of vitamin A in their tissues. I don't know about the brown bears as such but it has been documented in sled dogs that are living in an arctic environment for extended times.

Now both lead poisoning and vitamin A toxicity can cause a variety of neurological symptoms including irrational behavior, confusion and irritability. Either one or both are at least possible factors and only the toxicology reports would provide an answer.