Faith Slayer Daisho

"During the second age as most historians call it, a new source of celebration and tension began to appear. Divine power, whether these powers existed before hand, is for to priests, magi, and philosophers to debate and no serious historian should presume to know if the gods only came to our world at that time, or if they were here all along. The wide spread acceptance of divine presence led to many cultural and political changes. These are the things a historian should attend to. The Faith Wars were the first of these recorded and gave rise to cultural and political changes across the world. Many new enchantments were created the Faith Slayer Set being one of the most infamous. The cultural and political changes made by the influence of the divine appearing; the horrors, cultural changes, and political ones. These are the duty of a historian."

-Excerpt from the lecture notes of Master Historian Zhidi Taizong.

The Faith Slayer Set is an artifact created by the most powerful sorcerers of the Elven Shogunate Empire during the time of the faith war. Enchanted by elven magi, powerful elementals, and outsiders the set was created for a specific war . Crafted to go unnoticed, the Faith Slayer Set has a lacquered scabbard set that appears black in dim lighting and dark red in the full sun. The color was a popular choice at the time in the Shogunate Empire, while sheathed in their scabbards the blades shed no magical aura and are immune to most known means of magical tracking.
Like most sword sets in the Shogunate, the Faith Slayer set is daisho consisting of the traditional Dai-katana (the main long blade), Wakizashi (the shorter parrying blade), and Tanto. The set infers some skill on the wielder so that if the chosen champion fell another could pick the weapons up and be ready to carry on with better than average skill. The Faith Slayer Set as many might guess from the name were crafted by those who practiced druidism, elemental worship, or the worship and belief in various natural spirits and powers. Wanting to fight off these radicals and their gods. The Faith Slayer Set was crafted to be a nightmare to any of these deity worshipers who were unfortunate enough to encounter the warrior chosen to bare them on the battle field.
Each blade had it's own name and specific function and were a powerful magical item in and of themselves. Like most artifacts that are crafted in 'parts' the blade real potential comes to the fore when all three are carried by the same person. The katana was the holder of the name faith slayer after which the who set was called. The blade would cause bleeding wounds that were very difficult to close to any ordained faithful of any god. Worse yet the wounds wouldn't respond to divine healing. That was when the blade was being wielded as a single item.
The wakizashi was named Vow Taker. Vow Taker was not as deadly on the battle field but was more feared by clerics and temple warriors in general because each strike of the sword is reported to have diminished the connection that one had with their deity. Stripping away the powers and spells with each cut that a believer had been granted. Until the wounds had been healed (Vow Taker's wounds could be healed by divine magic), the powers that had been stripped away wouldn't return. Paladins would find themselves cut and sliced into being nothing more than a common fighter with no powers or ties to their deity. The real horror according to ancient records was that rumors were started that if you were killed with Vow Taker, you could not go to your god in the after life because the tie to your deity had been severed. Other records state that this was disproved by various priests later.
The Tanto of the set was named Heretic's Kiss. When insight and wisdom were found to be key elements in creating a connection to a deity and keeping it, Heretic's Kiss was invented. The tanto inflicts wounds on the mind and if you're unlucky they cannot be healed. Rendering clerics, priests, and all manner of holy champions; into mental invalids. Most feared by those who know the history of the set well, Heretic's Kiss can permanently render a life of service in a temple into a life of drooling and shuffling about. The tanto only affects those who are ordained in a faith, making it nothing more than an average knife, albeit a sharp one to to the common person.
The set when wielded by a single person becomes more powerful, exhibiting it's full status as an artifact rather than just as a magical item. Faith Slayer has a chance of breaking any divine weapon or armor that it's edge comes in contact with usually just cutting through the armor as if it were rotten cloth rather than any proper protection. Vow Taker, becomes capable of disrupting divine energy, allowing it to 'dispel' clerical magics that can be seen such as in cases of divine barriers of protection or conjured arms and armor. Heretic's Kiss worst of all become capable of doing what Vow Taker was rumored to be able to do. The small tanto can sever the divine link between mortal and deity. Needless to say the swords were hidden away at the end of the faith war. They were supposed to remain in a safe place and only be used again if the various clerics and temple goers decided to wage another war of conversion or death.
The blades are rumored to have been stolen repeatedly since the end of the war. One or two of them have shown up in history here and there as a single blade but no one has reunited the set since the end of the war. Considering what the effects of carrying all of them into battle are, perhaps it's for the best.