Many years ago, there existed a wealthy kingdom of Xenar. Its people were peaceful but strong. Their warriors were deemed unbeatable, their armour was fabled to be impenetrable, and their swords unbreakable. They never fought outside their lands, though, and only fought in defense of their kingdom. The spies of their enemies could offer no explanation to their kings and generals, other than the fact that anything which was taken to their lands made of opal became unbreakable, even to a blacksmith's forge. Those same items, on leaving the island of Xenar, lost their strength as if they had never been there at all. They were no use to anyone outside the land of Xenar.
One night, a hooded group of bandits crept into the castle of Xenar, overpowered the sentries who stood watch over in the Great Treasury, and stole a magical staff. The next morning, the kingdom was in an upheaval.
The Xenarum swords became heavy. The strength drained from their armour. Malkaron and his armies were ready, and took to battle against the Xenars. Without their shields or swords, the Xenars could not fight. They were killed, their cities were pillaged, and their castle burned. There were no survivors.
Word spread of this impossible conquest. Malkaron's army now wielded the magic to turn opal invincible. Wielding the Staff of Xenarum which held the X-Crystal, Malkaron's armies became the most famous and feared of any force. They were practically unstoppable.
Then one night, it is told, a silhouette of a man or beast was seen fleeing from Malkaron's palace, who disappeared into the night. The opal weapons and armor, once again, became normal.
Knowledge of what the X-Crystal is has always been a very tightly-kept mystery. Besides the Xenars, only a few scholars (like the Oracle) had enough resources and ancient histories to even know about it. Malkaron had learned of it only by piecing together bits of information acquired through torturing several Xenar prisoners over the years.
Binderak, a descendant of the Xenars, was the one who stole the X-Crystal back from Malkaron. He was seen by the Oracle carrying the StaffOfXenarum as he entered her tower to use her Travel Point. From there, he went into hiding on a remote island while he waited to recruit other Xenarum descendants and allies who would help reclaim his homeland.
About the same time that Binderak stole the Staff of Xenarum, Nostik was in Malkaron's army as one of his closer advisors. Because of his power, Malkaron had become corrupt. He would let anyone, man or beast, join his armies and soon they were nothing but monsters and savages. Nostik noticed that the Staff seemed to play a huge role during battles, as their weapons and armour turned light and hard whenever Malkaron was near them with the staff in his hands. Nostik asked one too many questions, and Malkaron had him imprisoned. The same night that Malkaron sent Nostik to the dungeon, Binderak got away with the Staff.
Malkaron was furious and tortured Nostik. Nostik escaped with the help of some friends and also had to go into hiding. Malkaron is looking for Nostik, so Nostik has to remain at the manor. His butler is his main front, and you 8 are the only people who he trusts won't give him away.
Malkaron, in the meantime, opened portals everywhere to try to find Nostik and the X-Crystal. Once you seal them shut, monsters will not attack you in those areas anymore. Sealing those portals is purely optional, however, but has the benefit that the other party members will join your party.
- that the Staff (or Crystal) of Xenarum is practically unheard-of (a well-guarded secret)
I really don't buy this story. Wouldn't somebody notice that the invincible armies are wearing opal? It isn't exactly common armor, being heavy and fragile and all. Even if it changed the opal to appear to be strong steel, or something unrecognizable, after somebody notices that any opal they bring to the land becomes unbreakable, the jig is up. Once the jig is up, any attacking army can bring opal armor for themselves. It would probably be easy for blacksmiths to make, since they wouldn't have to worry about strength. It would be invincible in battle.
To make this story coherent, perhaps instead of opal, it could be a special material, of which there is only one mine, and the mine is in LandOfXenar. I would probably forgo all the secrecy. It's nearly impossible to keep something like that secret. It would probably be easy to guard the mine when you have invincible guards.
Also, keep in mind that the warriors wouldn't be invincible just because their armor is unbreakable. Armor is useless when it is removed from you. I think it would be common for ambitious kings and warlords who want to take Xenar's power for themselves to salvage Xenar warrior's armor.
On the other hand, if, instead of this mysterious material being unbreakable, it made whoever wears it invincible, defeating the warriors might not be such a possibility. What happens when two people who are wearing this armor fight each other? Is it as lame as when Greek gods fight each other? Destruction all around, but no point in sight?