From a Planewalker thread.
About a thousand years ago a valiant knight from Celestia used the sword to kill an old evil god of a forgotten race in Dis on Baator’s second level. [Any ideas for the knight? Does this make sense? At this point in time Attaxa is a light sword – whatever that means, I haven’t figured it out yet. Amaterasu is the LG goddess of the sun.]
On the way back he was killed by Tiamat on Avernus near the skull tower and the sword was lost. Apparently Amaterasu’s light was bound in steel and brass. [Magic weapons get weaker away from their home plane; I thus wanted the dragon to send the sword to the swordsmith masters in the City of Brass, binding the light and turning it into fire. This explains the current state of the sword and offers a way to undo it eventually. Haven’t got much more than that.]
A Baatezu used the sword on a Prime against an aspect of Pazuzu, the lord of the Tengu (evil bird men). The battle was lost and Attaxa was claimed by the Tengu kings. When they allied themselves with the human empire of the eastern mountains in their fight against the fey of the swamps that covered the area of Kitsunemori a hundred years later, the Tengu lords presented king Ueshiba with the sword Attaxa. The demon lord Obox-Ob had built an empire ruled by Kappa (turtle demons) and Kumo (spider demons). The war was won and when Ueshiba died, the blade was buried with him. [This explains why the blade was buried with the king. It offers the potential of a sidequest to visit the Tengu eeries and some Obox-Ob, turtle-, or spider demon action.]
Somehow the sword was changed in the City of Brass – binding the forces of light, allowing the sword to be used by devil against demon. How did the sword get sold to the Baatezu. And who was it? Where does he live now? If he died on an material plane, I’m sure not much happened to him on his native plane. Did Tiamat plan this or was the sword simply sold in the City of Brass? If Tiamat planned this, what did she hope to achieve? Was the Baatezu that ended up with the sword in her service? What was he doing fighting Pazuzu on the Material Plane?
I think I’d love more plot secrets to allow my storyteller character moments to shine. She is important. She protects & saves. She figures things out and intuits who her friends and foes are. The others want interesting fights, cool treasure, and they like discovering that they are being betrayed and outwitting their foes at the last moment.
Using a gem for the sword is excellent. The first thing to unlock the sword’s power was to place a diamond worth 1000 or 5000 gp into its pommel. I felt that a diamond was best suited to represent celestial light.
I also like the idea of a ferocious sword with a mission: A drive to do something. I fear that “fight evil on sight” is a bit too simple. Perhaps a subsonic hum and a fierce light that announces “I am here to kill evil on sight” – that would provide interesting opportunities for roleplay without the player feeling that I was using the sword as a device to control the plot.
Of course being chased by over zealous lawful agents both good and evil bent on recovering the sword is a fantastic idea. I’ll just have to find an explanation for the error the good guys are making. (Or not, depending on how my players act in the future.)
Perhaps as follows. Amaterasu (or her agents) planned her mission to fail. The knight sent was Momotarō, prince of Peachblossom Castle on Celestia’s second layer and a confidante of Bahamut. Momotarō willingly sacrificed himself [or an aspect of his – not sure on the options the rules provide here?] in order to kill a minor god of no importance and thus deliver the sword into Tiamat’s claws. I guess they must have tried to trick Tiamat into doing something… Or maybe the sword coming from Tiamat would be passed on to the real target of the ruse. Somebody who would accept and use the sword. Maybe somebody smarter than Tiamat. [Any ideas?]
The plan must be that Amaterasu’s agents wants to place the sword such that it will be used against her enemies many centuries later on a Material Plane that only Tiamat knows. And that’s exactly what the party shall be doing. Of course the plan is either secret or forgotten, so that misguided champions of good will pursue the party once they either learn that they have the sword and no intentions of giving it back, or once they learn that they are using the sword for a (seemingly) nefarious purpose. Yikes… I’m trying to make up a celestial counter-plot to a fiendish plot.
So basically Ameterasu knows Tiamat has hatched a plan to bring a Material Plane under her dominion, but she has not discovered which one it was going to be. Perhaps by whispering arcane secrets into mortal ears that were never intended for human souls to bear. Insidiously these ideas secrets grew into arcane powers and at last her subjects were ready to discover the Codex of Draconic Gates [just made that one up – a book hidden away on a draconic demiplane, detailing how to summon an aspect of Tiamat, which is how I will reinterpret the ending of Red Hand of Doom].
So Amaterasu knows that she needs to trick Tiamat into delivering a weapon against herself to the very plane she intends to conquer a millennium hence.
She delivers the sword into Tiamat’s hands and manages to send word to a Baatezu known to be clever enough to outsmart Tiamat. This is accomplished by another multi-layered plan. And in the end the fiends fall for it. The sword is modified in a predictable way by the Baatezu as Amaterasus agents have anticipated: It is brought to the City of Brass and the celestial light is bound and chained to fire and destruction. But they had hidden secrets into the blade that would take a thousand years to unravel.
The sword was built to loose power. Slowly at first, but ever faster in the end, the sword drank the energies of those around it, storing them in extradimensional pockets away from prying eyes. And so the Baatezu was betrayed at first. And so the Tengu kings were betrayed as well. So was Ueshiba, king of men, betrayed at last. The sword had reverted to a simple +1 weapon.
Only now that Tiamat’s agents are returning to the Prime Material world is the sword regaining its power. The wielder will have to speed the sword along: Awaken its dormant abilities, learn to master its secret stores of power hidden away in spaces too twisted for mortal minds to understand. Restoring the diamond reestablished the original “mission” of the sword, leading its wielder back to the City of Brass, where agents of Amaterasu will recognize the sword and unlock the next level of abilities. At the same time the agents will have their own agendas, hopefully diverging from the party’s goals. [Maybe I’ll reuse the idea of a monkey king? Not sure whether a falcon king would be too close to Pazuzu…]
Should the party decide to fulfill the original mission, they will have to destroy Tiamat’s aspect on their Material Plane, and since it will be impossible to kill all those that have learnt of her terrible secrets, the only way to secure their plane will be to find and destroy the Codex of Draconic Gates, severing easy access between their home plane and Avernus.
The “stored energies” of the sword might also be used in a final battle as suggested by The Great Hippo – “living lightning, crackling and whipping across entire fields of battle, scorching evil in its path.” I like that.