Pondering Research Tablet I
At minimum, Marchosias doesn't understand why it's snowing. But I suspect he's referring to Ewefall's entire situation when he notes "cause unknown". He doesn't know why Ewefall is Godless and in ruins either.
The snow is unnatural. It makes sense for there to constantly be snow towards the peak, because the altitude would make it so. But towards the base there shouldn't be year-round snow. Especially because there isn't anywhere else in the lands (including places at similar or even higher altitudes) where that snow is present.
It would seem the Lands don't get cold enough to snow period. Upon activating Winter for the first time, Lamb's Followers are scared of the snow—because they don't know what it is. Plimbo is also an interesting point of reference for this, because they chose not to make him use the word "snow". He calls it funny weather; which he heard about through stories passed down by his family. A story that's about 150 - 200 years old.
Marchosias describing the place as "godless" at all is... curious. Like, it's not wrong. But at the same time, there's very much a bunch of Gods present, they're just dead. That detail feels like something the Aspiring God Killer would comment on. (and I would argue the Sausage Angel's still alive?? It's halo is active.)
The graves are presumably the ones in Woolhaven, but Woolhaven isn't the only site of ruins. The temple-area we can sometimes encounter (which is entirely disconnected from Woolhaven) are ruins too. And the wool rooms. Arguably, even the statue rooms.
Two, maybe three NPCs comment on how the mountain "isn't what it once was". This phrasing is the same one used to describe Shamura and Yngya.
Shamura lost their mind—literally and figuratively. In the aftermath of their death, Followers remember them for being crazy (aka "mad"). They're notably not all that lucid. At any given moment their mind may be stuck in the past, and they won't be aware of that fact when interacting with those in the present.
Yngya's heart and mind were literally separated by her Disciples for the sake of the ritual. So the body she returned to when Lamb resurrected her was missing one or the other. It's debatable which one, so I'm undecided.
The same entity takes the form of both a heart and a head. "Using" her heart for the ritual could mean that it was offered up and consumed—the same way Lamb uses items for rituals—and not just hooked up to the mountain's guts like a car battery.
Both of their situations provide more context to each other and the mountain. Yngya was apart of the rot, but she's not responsible for the actions of Rotten Yngya—because she was never in control or even conscious. Yngya and Shamura were basically passengers in their own body.
Is it. Is it literally a different mountain? Adding Not-Mountain to the roster??
How... convenient that they had a ritual on-hand to turn the mountain into a living being that can house + sustain a heart and create the rot. And those had to be separate actions, because the rot doesn't need the mountain to exist. If anything, the mountain is hindering it.
It was no coincidence-- The Disciples didn't give the mountain life, they revived it into a weird zombie. MEANING...
The mountain was already alive once. It was the "body" of some other Monster/God/Titan-like being who died—likely before the purge.
Was that the key to staying hidden for so long? Hiding in someone else's corpse? Beneath a woolly hide, if you will? Was this corpse, perhaps, also capable of morphing it's appearance like the Rotten Heart can?
The Mountain is the Frankenstein's monster lol
Definitely something about the placement of the heart. It means we only have half the body... Don't generally keep your heart around your ass.
Unless of course you're a cephalopod.