SWORD SPIRIT - By Bill Silvey

Frequency: Very Rare
Number Appearing: 1
Armor Class: 0
Move: 6"
Hit Dice: 10 (D10)
% In Lair: 0%
Treasure Type: R
No. Of Attacks: 1
Damage/Attack: By Weapon (+3)
Special Attacks: See Below
Special Defense: See Below
Magical Resistance: 90%
Intelligence: Genius
Alignment: Lawful Good
Size: M
Psionic Ability: Nil
Attack/Defense Modes: Nil
Level/X.P. Value
XII/10600 + 35/H.P.

The Sword Spirit is a rare to the point of being almost mythical being sent from the outer planes to avenge a specific misdeed: When an Intelligent, +5 Holy Avenger with an Ego of 18 or higher is destroyed before it's wielder (who must, at the time, be aligned of absolute Law and Good and have been that way unswervingly throughout their lives; e.g., no Girdle of Alignment Change) can complete a great crusade against a great evil, and that destruction results in not only the destruction of the sword but in the death of the wielder and that destruction came about by an act of great treachery (such as a fellow campaigner betraying the adventuring party), there is a 1% chance that a deity (5% if the deity of the deceased character) will grant the "spirit" or "soul" of the Sword an existence on the Prime Material Plane to avenge itself.

This life will take the form of a "normal" mortal being, almost always a Paladin, who will seek to undo or avenge the injustice which brought about both the destruction of it and it's wielder. This "person" will appear as a full-grown mortal (50% chance of being female), and it's statistics are to be determined by the Dungeon master. Each statistic will be 12+1d6 save Strength, which is always 18/99. The Spirit Sword fights at the 10th level of ability as either a fighter or Paladin, and can use all Paladin abilities at that level (if indeed it is a Paladin type which is created).

They will have a full knowledge of the area of the world where the wielder was last, who his or her comrades were, and where to find them. If they all perished with the wielder, the Sword Spirit will seek to recruit a new party of adventurers to join it (all normal Charisma bonuses apply). It will only call upon those who are Lawful Good in alignment - it can inherently sense this. A cache of treasure who's location is known only to the Sword Spirit will be sent with the Sword Spirit on their journey to the Prime Material Plane. This will never be found by anyone other than the Spirit, although once it is uncovered if it is not taken by him/her, others can then find it.

The resolution and determination of the Sword Spirit is absolute and unswerving. They seek only to avenge themselves and set right any misdeeds done due to it's "failure". If, in the mind of the Sword Spirit, a particular quest or adventure can help the overall goal of avenging itself, it will agree. If it doubts the quest at all, it will take great persuasion to convince the Sword Spirit otherwise.

The Sword Spirit's resistance to magic is very great; any spells which are surreptitiously cast at it (such as Charm Person or Geas) will 90% of the time have no effect whatsoever, furthermore, if the Sword Spirit makes a successful saving throw after Magic Resistance is checked, they will know immediately that someone attempted to cast the spell, who that person was, and where they are (even if Invisible or Hiding In Shadows). 

The personal disposition of the Sword Spirit is one of fierce determination and unwavering zeal.

Upon completion of the crusade to avenge itself, the Spirit will depart the body which will immediately fade away, leaving whatever treasure remains after it originally appeared.

Legend tells of one "negative" Spirit Sword which existed which was as diabolical as the others are pure, but it is largely regarded as myth.