A Few Magic Swords

Plutonium Sword - One-handed, heavy, d8 damage. Forged of literal death metal. Drawing the sword from its heavy, protective scabbard, exposes the wielder to destructive radiance but an enemy struck by this dread blade will quickly sicken and die.

• Takes up two inventory slots (or double a normal sword). 
• When drawn, and for every Turn that the sword is out of it's scabbard, the person wielding the Plutonium sword permanently reduces their maximum hit points by 1.
• Anyone struck by the sword takes an additional d12 damage at the end of each of their turns until they die as their body twists and mutates. They'll grow razor sharp spines of coral from their bones, or vomit out their organs, or their flesh will peel off in strips like a string-cheese. Only the strongest magic can reverse this.
• This is a legendary artifact, and once a wielder is identified, they'll be hunted by those wishing to take it.

Rictus - Smallsword, finesse, d6 damage. If maximum damage is rolled, the target is paralyzed until the sword is removed. Might not work on non-humanoids or those with strong magical protection.

A fun encounter: Adventurers discover a vampire pinned to the wall by a smallsword (detects as magic). While impaled, the monster is inert, removing the sword frees it.

 

Ink Knife - Gladius, d6 damage. A tattoo of a sword on the inside of a person's forearm. When rubbed, it manifests as a physical sword in their hand. Rubbing the pommel returns it to tattoo form. 

Themis, Sword of Law - Executioner's sword, two-handed, d10 damage, Deals +3 damage vs. bandits, rebels and criminals. If used by a lawbreaker, it acts as a -3 cursed sword that will wound it's wielder on an attack role of 3 or lower. 

Illuminare -  Longsword, versatile,  d8/d10 damage. When drawn from the scabbard, it casts the Light spell on itself. To re-charge, it must be left in the sun for one full day.  

A few more from the legends:

Harpe: Bronze sickle sword, d6, +1 damage. Never dulls. Rumored to be older than human history.

Tyrfing: Ancient iron sword. d8, +1 damage. Shines like a torch when drawn. Cursed: If drawn from the scabbard, it can't be released from the hand until it has killed. 

Nail: Heirloom sword, broken at the end.+1 to hit, d8 damage. Roll damage with advantage vs. reptiles.

Durendal: Holy longsword. +2 to hit, +2 to damage. Can cut through stone. Relic of the paladin Roland.  

Dyrnwyn: White-hilted, arming sword, d8 damage, +1 to hit for it's owner. If loaned to anyone else, it also deals +2 damage. Anyone borrowing it, will feel compelled to return it once used and will refuse to ever borrow it again.