That's what MMORPG's are about I yet to see one that revolves around 1 storyline or if any...
Back on topic XD...
I would like to hear the Valkyrie, Thanatos, and Ktullanux (This one especially since I would like to know if you ever get that boy in ice out or if he's there for a reason) Stories...
Valkyrie: There really isn't much of a story here as far as I know =/
Thanatos: Thanatos tower was originally built by demons and it was used to summon more demons from hell during the 1000 year war. This is where Satan Morroc actually originated from. Satan Morroc used the Thanatos tower to gather minions, after a while the assasins guild sent a group of SinX's to try and defeat satan morroc. Amongst this group there was a man called Thanatos and a woman called Lucil. Lucil and Thanatos fell in love.
There was first a fight in the Thanatos tower with Lucil's group and Satan Morroc. Her group managed to wound satan morroc apparently forcing it to retreat to south, to a nameless desert.
There Satan Morroc fought against Lucil and I'm guessing she died in that battle. Thanatos came after them and managed to seal Satan Morroc. However mourning the death of his beloved he was engulfed by rage, he went back to Thanatos tower and stayed there mourning after his beloved. I'm guessing he went through the gate which was used to summon demonss, that would explain why he's released after you open the gate in the quest.
Now after a long time the Rekenber corporation (Same group responsible for Biolabs) decided to renovate the tower to it's former glory. When investigating the tower one man learns the truth about it and secretly sealed the gate to hell which was used to summon creatures. He sealed the gate, but before sealing it he investigated it and noticed that the gate gets it's power from the charm stones. He then separately sealed all the charm stones in order to prevent anyone from misusing the gate.
I'm not 100% sure this is accurate, I mainly used the quest script from eA Thanatos tower script to base that story. I'm pretty sure it's very close to the original quest and original storyline.
Ktullanux: Ktull's origins are never explained, it has always been in the Ice Caves. However there is a backstory to the boy there.
In Rachel it is tradition that the girl who most resembles goddess Freya is chosen as the pope of Rachel. The pope is chosen on birth and cut off from her family, she's taken to the main temple and raised as a pope. However when the current pope was born she was born with a brother equally as beautiful who beared great resemblance to her sister. The priests of Rachel, knowing that this girl must be the pope. But fearing that her brother might cause the believers to doubt the girls divinity. However believeing that the birth was of divine origin they simply could not kill the boy in fear of divine judgment from Freya.
So they made a deal with the monster Ktullanux in Ice Cavern. The boy would be sealed in the bottom of the Ice Caves for all eternity and Ktullanux would guard him. This way no one would ever learn the truth and they would not have to kill the boy.
You can find about this in the Rachel sanctuary after gaining access there. There's supposed to be an NPC in the bookshelf on ra_san04 (137, 48) from where you can find out about this.