"This throne seems to suppress all magic. Looks like it was designed to confine someone very powerful, who then broke free together with one of the manacles. I would advise to stay away from it. Are there any other exits?"
Raulzig will start scouring the perimeter of the room for secret doors.
Perception:1d20 + 34 ⇒ (1) + 34 = 35

Lefty will try to help, though he's no match for the sharp-eyed gnome.

perception:1d20 + 20 ⇒ (5) + 20 = 25

Could this be where Koschtchie was held? The anti-magic effect may have been used to suppress his powers so he couldn't just pop out of his bonds. These creatures may have been his guardians. Or his victims.

The thought of looking for an angry demon god with a half millennium-long grudge to settle makes the elf a little uneasy.

There may be a trail of some sort. Whatever was here has taken its leave.

The tracks lead to a door to the north, opening up to an area where a natural fissure has formed in the ice of the waterfall where it meets the stone of the cliff face, climbing to a height of 160 feet.

The rock face itself is broken by a series of shallow, natural terraces covered by only a few feet of ice. The ice is transparent enough to see the blackened corpses of hundreds of human warriors manacled to the cliff face. Many of the manacles hang empty or hold only the dismembered remnants of limbs. In some places, the ice has actually been chipped away to expose the rock wall, and the exposed manacles hang empty —- their previous occupants conspicuously absent.

Sorry for the absence, I'm back"Wow. Just... wow. I knew that the village was magically frozen, but seeing it is another matter entirely... This sends even more chills through my spine, even though it's chilly here by itself."
Raulzig inspects the wall, checking if there is a way to climb up the cliff face.
Perception:1d20 + 34 ⇒ (12) + 34 = 46"And those people who were torn away from here - I wonder who needed their bodies and for what purpose... Though maybe I'd prefer not to know."

As you float over the ice to the crevasse, shadowy arms emerge from the wall. One of them touches Lefty, apparently not hampered by the elf's invisibility, and he feels his strength desert him. 8 pts. Strength damage

Though other arms are visible emerging from the walls of the room, they don't seem to move toward the other four of you.

Init":1d20 + 2 ⇒ (6) + 2 = 8"Make way..." Krokod manages to sputter before he is once again speaking in the tongue of fire.
Krokod chants and lets loose a fireball at the arms when his friends seem out of range.

10d6 ⇒ (2, 4, 5, 1, 2, 2, 1, 6, 5, 5) = 33Ref DC 22 for half. Also Burning Magic (Su): Whenever a creature fails a saving throw and takes fire damage from one of your spells, it catches on fire. This fire deals 1 point of fire damage per spell level at
the beginning of the burning creature’s turn. The fire lasts for 1d4 rounds, but it can be extinguished as a move action if the creature succeeds at a Ref lex save (using the spell’s DC).
Dousing the creature with water as a standard action grants a +2 bonus on this save, while immersing the creature in water automatically extinguishes the fire. Spells that do not grant a save do not cause a creature to catch on fire.

Ryarg and Bern have nothing currently available to combat shadowy arms that wither your strength at a touch. Since they don't seem to be coming at them at the moment, he's content to wait for the spell slingers to do their thing.

He does growl slightly, however, when the fireball seems to have no effect.

This would be a great time to spam 1d4+2 lantern archons, but alas, they're only on the summon monster list.

The astral plane is kinda murky (p. 440). I'm hoping to move down the crevasse without being touched again, and spotting an egress at the bottom. I'll calculate the distance, and d. door us all to that area.

If I can't spot it astrally, I'll use my bonded item to go ethereal. Unless, of course, the other guys figure out how to get rid of the haunt, or whatever it is.

It depends on what Lefty can see on the Astral plane. If he can see a route, we're good. If not, he has to go ethereal, which costs him his free spell for the day. We need to get past this, and keep moving, IMO. He'll have to cast D.Door twice. Lucky for us, he can. If planar magic doesn't work in here, he burns a little magic that won't help, anyway.

Lefty, the crevasse leads about four hundred feet down, to a low grotto carved through the core of the vast ice formation. The walls, floor, and fifteen-foot-high ceiling are irregular and rough-hewn, but smoothed as if by melting and refreezing. A cold mist fills the air, making it difficult to see in this labyrinth of ice tunnels.

It's unlikely that there are any traps, magic or otherwise, he can detect across the planes, but the plucky elf takes a round to see what he sees, not needing to concentrate to use arcane sight to note any magic auras. That's unlikely, too.

2/16 rounds? I assume he moved there the 1st round?

Next round, he'll float on in. Gotta teleport past the obvious traps, if it can be done in here. Astral plane seems to work okay. If not, we got problems! LOL

Raulzig will observe the tentacles for a while, and if he concludes they are not aggressive, he will attempt to backtrack and see if there were any other pathways they have missed. He will use the right-hand rule and leave markings on the floor every 30 feet to trace his route, until he finds a door or passage they have not been to.