If your unknown force was giving so much light, that it was possible to see clearly, why wasn't it possible to see said light without climbing a tree?
A light in the dark is visible over great distances. Especially when there's nothing in the way, which there isn't it's a flat area, no trees, no big boulders. And the fact, that it's a slope doesn't change much in that aspect.
It is not possible to see every part of the slope through the forest. And the light of unknown power does not illuminate the surroundings, it only illuminates itself. Not like a Sun. Like a firefly... After all, they knew that the unknown Force was very dangerous and deadly. That's why they took a good look around. Maybe the two Yurides went out together and spied on. And it was imperative for them to return to the tent. The weather was getting colder. The weather, which was -10 degrees in the evening, would become -20 or even colder in the following hours. And the night was very long. The sun rises around 9:20 am. So after warming up a little on the Cedar, the two Yurides couldn't see anything, so they decided to turn around. In any case, the two Yuri and Dubininas did not have their tops. their condition was serious. But halfway back, the unknown Force attacked. And they all died unfortunately. May Allah forgive them all and put them in Paradise. Amine
Okay, I try to break this into parts:
1. "It is not possible to see every part of the slope through the forest. "
Agreed, that's why you postulate, they went to the cedar. Sounds logical to me.
2. "And the light of unknown power does not illuminate the surroundings, it only illuminates itself. Not like a Sun. Like a firefly... "
I'd like to ask, what that might be, but I imagine you're as much at a loss there as I am. Nevertheless it is enough for it to illuminate itself. You can see fireflies from some distance. And I'd say, a force that was able to destroy the bones of people, as you postulate, must be much bigger than a firefly. Therefore it should be visible from further afar than a firefly.
3. "After all, they knew that the unknown Force was very dangerous and deadly. That's why they took a good look around. Maybe the two Yurides went out together and spied on."
Sounds kinda logical, though I disagree with your premises. That's another story, though.
4. "And it was imperative for them to return to the tent. The weather was getting colder. The weather, which was -10 degrees in the evening, would become -20 or even colder in the following hours."
Agreed. The whether analysis suggests temperatures around -30°C. and felt temperatures of around -50°C.
5. "And the night was very long. The sun rises around 9:20 am."
Check.
6. "So after warming up a little on the Cedar, the two Yurides couldn't see anything, so they decided to turn around."
I am not sure, if I understand you correctly there. They turned around? So they went back into the woods to where the others were waiting?
All in all: If one believes in your unknown force, your theory is pretty consistent. So now let's speculate as to what that force could have been. What do you believe killed them?