The Sword of Law

Everyone knows about the Lords of Chaos, who foment madness in the wasteland east of the civilized nations. But few know of the Lords of Law, who dwell far across the sea to the west, for they do not meddle in the affairs of mortal men. Anymore. But long ago they sent a champion to fight chaos, and this was his sword, a sword perfect for that fight.

The Sword of Law does 5 damage, 8 damage if wielded two-handed. The wielder strikes as if they rolled an 11. If it hits a creature of pure chaos, that creature is destroyed if an 11 would fail its save vs. death. The sword is perfectly logical, and will not hesitate to explain why what you're doing is illogical.

Ethereal Sword

During the enlightened ages of the rule of the Solarian Empire, there was an archmage named Egon. Egon loved to plunder tombs, but after a particularly painful encounter with a ghost aged his beloved Janine 20 years, Egon decided to create a sword that would be particularly effective against ghosts.

The ethereal sword appear to just be a hilt, as the blade exists entirely on the ethereal plane. It has no effect on creatures that lack a substantial presence on the ethereal plane, such as humans, humanoids, and most monsters. However, against creatures with a substantial connection to the ethereal plane, it functions as a sword +2. And against creatures that are fully ethereal, the sword deals double damage. As long as he wielded this sword, it was said that Egon was not afraid of any ghosts.

More magic swords!

Shamelessly stolen from Reynaldo Madrinan, with some edits.

Mockery of Honor - Lady Korinne Loras was a knight of Solaria, and in charge of an expedition to Morachi to retrieve the Fulcrum of Winter and sworn to bring it back to Solarium. When she defeated the mummified guardians of the Fulcrum, however, she turned on her companions, using the power of the Fulcrum to kill them all. She attempted to use the Fulcrum to replace Koschei as prince of winter. Koschei won that battle, but the Fulcrum was lost. Stained with the betrayal of a once great knight, this +2 broadsword affords its master a +2 bonus to all saving throws and immunity to all forms of fear and disease. It glimmers softly in the presence of evil and drips fresh gore when near someone truly good.

 Discordant Razor - This weapon's movements seem wild and erratic, no matter how skilled the wielder happens to be. Being struck by the sword further confuses the target, who must succeed a saving throw versus spell or have their next action altered negatively by the Razor's power. Victims of this ability will preform in the exact opposite manner of their intent. This sword is a chaotic vorpal sword often wielded by champions of chaos.

5 Intelligent Swords

In Arden Est, intelligent swords are created when their owner perishes and his or her soul, rather than passing on, inhabits the weapon they bear instead. Here are five such swords:

'Vajra', Sword +1, light 30' radius, INT 9, EGO 3, AL L, speaks through empathy.
Detects evil, invisible or hidden, and traps.
Vajra was owned by an enthusiastic, but none too bright, cleric of Fayon named Marcus. Marcus desperately wanted to be an adventurer, but his order, fearing for him in his foolishness, attempted to dissuade him. When he would not be dissuaded, they gave him a magic sword that shed light, hoping that it would light his way. Sadly, Marcus fell in with the Family, a mafioso type of thieves guild that Marcus thought was just a normal family business. While attempting to retrieve a golden falcon for them from a tomb, Marcus was killed by a pit trap.

'Almace', Sword +1, luck blade, 2 wishes, INT 9, EGO 5, AL L, speaks through empathy
Detects traps, metals, and invisible or hidden.
Chris was a halfling thief who often performed heists far beyond his ability. He attributed his success to skill, but in fact, he was always merely incredibly lucky. His luck ran out when the mound of rubies he was climbing turned out to be a red dragon, who incinerated him.

'Gram', Sword +1, +2 vs. spell-casters, INT 7, EGO 10, AL C, speaks through empathy
Detects magic
'Gram' was the blade of a barbarian named Gram who hated magic-users. Whenever the wielder of this blade is in the presence of a wizard, she feels a compulsion to slay them. Gram left a streak of dead witches and warlocks throughout Fogelon, until a wizard named Wilhelm proved to be too much for him.

'Skofnung', Sword +3, vorpal, INT 12, EGO 6, AL L, speaks Common, Morachi, Dwarven, and Thyranian, can read languages. Detects magic and invisible. Can levitate the bearer for 15 turns.
'Skofnung' was wielded by Thorkel, a warrior from the early days of the Solarian Empire. Thorkel led a band of barbarians against the attempts of Solaria to expand into Fogelon, but he was eventually slain when a Solarian mage summoned an invisible stalker to assassinate him.

'Gallowglass', 2-H Sword +1, +3 vs. undead, INT 8, EGO 6, AL L
Detects secret doors, traps.
Reed was a famed tomb robber, best known for a legendary set of thieves' tools. He commissioned Gallowglass to help him defeat the undead who tended to guard the more lucrative of these tombs. His friend, the sage Zakarios, worked with him on a translation of the epic story of the defeat of the lich king of Surash-Knaak, leading them to believe they knew where the lich king, and his treasure, was interred. They were correct: however, they did not know that the tomb was guarded by a massive iron golem. Zakarios escaped with the sword containing the soul of his friend, but himself was killed by bandits shortly thereafter.