Grey Blade of Vagnu

The Grey Blade of Vagnu, or commonly called "The Grey Blade" is a artifact that was until recently hidden in the underdark. Currently in possession of a party of adventerers it has left it's resting place after 1,000 years.

History
Forged by the Fey God "Payama" as part of his trinity blades. The Grey Blade was once known as the "Sealing Blade". It remained in his cache until great need arose and sometime during the "Great Drow Era" when a unknown warrior came to his alter and requested a way to fight to protect his people from the evil. Under careful consideration of the powers and it's use, Payama gifted the warrior with the Grey Blade.

For a month and a day the warrior fought the beast, which is remembered only in erata history as a Draconic evil. At the peak of noon, with blade shining under the sun, the warrior plunged the blade into the back of the beast, sealing away the powers of the beast, descending it into a deep slumber. As the creature slept and it's body sank into the Underdark, our hero fell atop the blade, his body spent and with the creature sank into myth, hidden by the earth.

Properties
The entirety of the blade is forged of one piece of meteoric iron, handle and blade. Though it is a dull iron look it also possesses a small luster as the blade is made using a forgotten method, making the blade indestructible by any method save for divine interaction. This gives the blade a reverse sunder as any attempt to sunder it instead reverses on the attacker.

The Grey Blade base stats:
 * Long sword: 1d8 /19-20x2, slashing damage.
 * The blade is Meteoric Iron, Making it a +1 Masterwork weapon.
 * The weapon is indestructible through mythic means, reverse all sunder damage onto attacker.
 * The blade gives a -2 to attack due to its off putting weight, but adds +2 onto damage.
 * Treat as cold iron for purposes of damage reduction.

Powers
If and when a proper divine connection for the blade is established, it's true powers shall be revealed.
 * + 5 Long sword: 1d8 /19-20 x2, slashing damage.
 * Treated as Cold Iron & Adamantine
 * Undetectable: The wielder or impaled is now undetectable by any magic means.
 * Truestrike: 1/1d4 rd.
 * Impaling: On a Critical hit, roll a grapple check with no Attack of Opportunity. If successful, add 1d10/rd on top of weapon damage. The weapon is considered grappled but the wielder is not. Must roll a STR check of DC 25, to remove. This adds another 1d10 of damage.
 * Master Critical: The Grey blade can critical hit any type of creature or item. This includes undead, constructs etc.
 * Guiding Light: as the spell daylight but instead of an aura it becomes a line of light pointing towards the desired target. This reveals weak points when directed at an enemy. These weakpoints show up as glyphs on the body and give the party a +2 to hits and crit confirm.
 * Sealing: When the blade is impaled it seals targets: Magical abilities, supernatural abilities etc.