Unenlightened Enigmas <Cliffs of Lommond artifact>

You find yourselves resting on the wild shores of the Cliffs of Lommond. An ancient and breathtaking landmass. The Crashing of the waves echo in your ears as you sleep, as comfortably as you can, on the cold ground. As you slumber, you see the same vision that compelled you to these lands. The dream you saw before any of you knew one another. The dream of the world being overtaken by fire, death, and madness. You remember the flash of words "Your destiny, Where the cliff greets the sea", and it seems to make more sense to you now.
Soleio you also see this vision for the first time and it is quite jarring and foreign to you. But given what you have already seen, it kind of makes sense on some level.

Your night proceeds on and the Dawn arrives and you are greeted by an overcast day. Sea spray mixed with rain pelts you as the Druid hut disappears.
What would you like to do?

You make your way south following the coastline.
a few miles ahead, you come to these scattered boulders strewn along the green meadows. Some of them you have deduced from your previous trip here, that they are burial cairns and entrances to various crypts. Ahead of you, you can see 5 cloaked figures herding what look like civilian villagers into this newly opened cairn. their hands are bound. There are also some dead humanoids laying on the grass motionless. What are you doing?
::The cultists Engage the party and will summon 8 Manes and One Hezrou
Encounter Party Vs. 4 Cultists (And maybe a Barlgura and 3 Manes)::
One of the Stone Crypts has been broken open. The black sunken foreboding opening yawns back at you as a chilling wind whips out from within the cavernous structure.
You make Your way down into the depths of this Crypt. The darkness immediately over takes you as you are in complete blackness. You make your way through this narrow passage way and you begin to see fire light ahead of you.
As you enter
((Ghosts will constantly harass the party as they make their way in. They will try to "Spook" them and possess them. If one of the party members gets possessed. They will speak (in the voice of the ghost)
"Tread no further mortals. There is great evil down here. My friends and I mean you no harm. But we must implore you not to venture further. There are fouler and more malevolent things down below.
Long ago, wicked men ventured down here to hide an item of powerful evil magic, It tainted the very air and spirits down here. The wicked men who were slain here were gifted by some evil force with undeath and great power. They are not to be trifled with... Stay away!"

2 Wraiths and 4 Wights wander the tunnels and passageways of this cairn waiting to attack players who venture too far.

Ghast and 2 Ghouls wait in the lower chamber
______________________
In the hallway just before the door, there is a carving on the wall. It depicts a deformed, grotesque figure. It's form is wholly unknown to you.

You perform one casting of the Chime of Opening. A clear bell like tone rings out and the door in front of you clicks as it unlocks. ::Pressing the door::
It swings freely. You move through this long tunnel-like archway which opens up into this cavernous chamber. Torches and pyres light the area around you. high vaulted ceilings tower above you at least 20-30 feet. The rough cavern floor gives way to hewn stone, this chamber looks to have been crafted by gifted hands. Carved Pillars and destroyed statues stand affixed in all directions. On the stone floor you begin to see splatters of fresh blood. It grows in volume the further into this chamber you go. Deeper still you begin to see the source of the blood. Bodies of all different races and sizes litter the floor, A look of sheer terror and torment frozen on their faces. Their bodies look emaciated and dessicated from the blood loss as if they've been completely drained.
(DC10 Investigation) These bodies are cultists as well as civilians. Like some great mass sacrifice was performed.
The path stretches on for about 50 feet. At the end of which you see a pool of red liquid (Presumably Blood) Bubbling and Roiling before you. Inside of it you can see familiar looking gems bubbling up to the surface. The whole thing looks like a giant stew.
Beyond you see The dark stone floor stops abruptly at what can only be described as a giant black ziggurat (Like a step pyramid [Think Babylonian, aztec])
It appears as though # cultists are standing but are covered in blood and look somewhat wounded. Along with them there is a demon of some type. You see it has a horned, boar face, a portly primate like body, and small rudimentary wings. It too is covered in blood though it doesn't look like its own.
What are you guys doing?
The Cultist sees you and smiles this demented toothy smile Cult fanatic: "We that are left, are the chosen, And I - am the vessel! The bringer of entropy!"
You see he's holding a black twisted ceremonial looking dagger and the veins in his arms and face seem to be coursing black liquid. His EYES from under his hood appear bloodshot and tired.

::Combat Party Vs. 3 Cultists + 1 Cult Fantatic + 1 Nalfeshnee:: Once complete:
an unnatural Silence fills the black chamber you are in. You hear the blood in your ears pulsating.
then a low rumble starts from under your feet. You watch as a beam of black energy emits from the blood pool and arcs up and then hits the ziggurat itself before exploding upward. The blood and gems are now gone from this container that was holding it. The top wall of the ziggurat starts melting into this black goo as you see some sort of miasmal gas quickly escape from within. And then from inside the ziggurat you hear this inhuman howl and suddenly, a figure emerges breaking the door frame as it exits. It is this indescribable abomination. The closest approximation on this plane would be a large distorted Centaur of some type. It stands on 4 cloven hooved feet that move up black fur covered legs which emerge into a humanoid torso that appears covered in tar or some viscus liquid. It has two humanoid arms one of which grips a large spear. Its head appears to have its exposed skull grown over and where its eyes should be is solid bone with the black spiral of Tharizdun etched into it. The skin on its mouth is pulled back into a twisted permanent grin exposing sharp blackened teeth. What appear to be rudimentary antlers grow out of its head as well.
It turns to look at you and its smiling mouth flexes into an even bigger grin.

::encounter party vs. avatar of Tharizdun::
It will destroy the door the party entered through, Then poke a hole in the wall above pouring in sea water from above.
It will then split into 3 and teleport away leaving the party to figure out how to get out of there
The water will fill the chamber in 3 rounds the party can then swim out of the hole made.
15 ft. out into open ocean
Then 100 ft. to the surface (PCS can move 15 ft. each round. 30 if they dash) should take 3 rounds
Sharks will randomly attack PC's each round and swim away (taking bites)

You break the surface of the water and can see the cliffs ahead of you. Are you heading to the shore?