Hail all!
I present to you Tol-The Demon Slayer. This was once a memorable character of mine. If you would, let me know what you think, good or bad.
Description: This is a finely crafted Elven blade made from Mitheral. Engraved on the blade in Elven are the words "Demon Slayer". It has a 5000gp diamond embedded at the end of the hilt.
Background: It was crafted by the Bladesinger Yoland-Tol. Yoland-Tol dedicated his life to the removal of Tanari from the Prime Material Plane. This was because a powerful true Tanari attacked his village an destroyed a Tree of Life that his clan guarded. He spent many years hunting down this greater Tanari and in the process he defeated many lesser demons. He also accumulated the materials he would use to create a blade that would help him defeat the powerful Tanari. He even acquired a minor artifact which he traded to a cleric of Mystra in exchange for her blessing of the blade. When he reached high enough level he crafted the blade. Yoland-Tol infused the blade using the magic he acquired , he even sacrificed a few powerful magic items to gain their magical strength. He then brought it to the cleric of Mystra and through the cleric, Mystra blessed the blade.
Through magic auguries and divinations, Yoland-Tol was finally able to track down the greater Tanari. He traveled to its location and confronted it. It was in the process of bringing it's fortress from the Abyss across the planes into the Prime Material Plane. A great battle ensued. The fortress was in a planar state of fluctuation. Yoland-Tol was able to deliver the killing blow when the fortress had shifted to the Abyssal Plane, thereby destroying the Tanari forever. But in doing so, the resulting backlash, which Yoland-Tol knew would happen, killed the Bladesinger. He willingly gave his life for the total destruction of the Demon. The magical power that was released reacted with Mystra's blessing in a way no one would of imagined. It drew Yoland-Tol's essence into the blade. With the demon dead, the fortress returned to the Abyss leaving all things from the Prime Material Plane behind.
Properties: This is an intelligent long sword and it has the personality of Yoland-Tol. It now answers to the name Tol. It is Lawful in alignment. Any Chaotic creature that touches the weapon suffers 10 points of damage, save for half. It has a +4 enchantment, +6 vs Demons. It can speak in Elven and Demonspeech. If there is any hint of demonic activity in the area, it will force the user to seek it out and destroy it. If the wielder goes against Tol's wishes it will attempt to possess the wielder to finish the task. It prefers to be in the hands of a Paladin, Bladesinger or other Lawful fighter.
Abilities:
Detect demon or demonic influence 100' radius.
Hold demon on contact (which includes a hit), no save only magic resistance applies. Duration 4d6 rounds.
Teleport w/o Error, as per the spell, six times a day.
Tele-track: once Tol contacts a demon and it teleports away, it can use one of its Teleport w/o Errors to bring the wielder to the demon's new location.
Heal, as per the spell, once a day.
Provides 50% magic resistance to demonic spells or influences. (DM's digression)
Personality: It has a stoic personality. Yoland-Tol never found life enjoyable like the other elves because of his clan's failure as guardians. He had become obsessed with the destruction of demons and it carries over to the blade. It will only talk when spoken to or if Tanari are in the area it will call to them and taunt them in Demonspeech. Otherwise Tol will let the wielder do as he wants as long as it don't conflict with Tol's Lawful nature.
Destruction: This blade is indestructible because of Mystra's blessing. If she should remove the blessing, then it can be destroyed as a normal magical weapon or Tol will sacrifice itself to destroy a true Tanari on it's home plane.