Valley of Crownlost
The sword hates undead and aberrant creatures.
Property: You gain a +1 bonus to the attack rolls and the damage rolls you make with this sword.
An undead or aberrant creature that touches the weapon experiences strong revulsion. If it maintains contact with the weapon for 1 round, the creature takes 3d6 psychic damage. That creature continues to take this damage each time it starts its turn holding or carrying the weapon.
When a creature holding or carrying the blade acts out of accordance with the blade’s wishes, they must succeed on a DC 5 charisma check. Failed Save: the creature is compelled into violent action against the weapon’s enemies. Successful Save: the target is immune to the Raven’s Onus compulsion for the next 24 hours.
Property (Attuned): The sword deals 1d8 extra radiant damage on hits against aberrations or undead.
Whenever you draw this weapon, all creatures and objects within a 30-foot-radius sphere take on a monochrome color and glow with a dull ambient light. All other sources of light and darkness are rendered ineffective inside this sphere.
Once per day, the sword can be used to cast turn undead using your class level plus proficiency bonus in place of cleric level. All aberrant creatures, other than the caster, are subject to the effects of turn undead.
The blade was once infused with the radiant light of the sun. It lay dormant for several decades at the bottom of a cave lake with the remains of its former owner, a paladin. It was recovered almost by happenstance by human ranger who retrieved it from the pool. The human himself was infused with the power of the goddess of death, the Raven Queen. When the Queen’s chosen took possession of the blade, the weapon was corrupted by his touch. It no longer craved the sunlight, instead the sword grew to hate undead and aberrant creatures and any who sought to disrupt the cycle of life towards death.