The Relic (Excelis Dawns)

The Relic was a device that was powered by life energy and could affect souls.

The Relic was made to look like a gold lamé French handbag so Iris Wildthyme would not suspect its true purpose. She was made to believe she had bought it on Hyspero. (AUDIO: Excelis Dawns)

The Doctor described it as 'a celestial aboration' that was designed for a higher plane. (TV: Excelis Decays)

History
The Relic was a weapon made by enemies of an immortal war queen who was trying new peaceful ways, getting Iris Wildthyme (who was the only one the queen trusted to negotiate the peace (Iris claimed the usual bloke had an ear infection)) drunk and using a mind probe on her and brainwashing so she wouldn't have any knowledge of what she was doing. The Relic was made in a form appealing to Iris so she would not suspect it. (Audio: The Plague Herds of Excelis)

Believing she bought The Relic at a bazaar on Hyspero, Iris brought it to Artaris and went on to loose (as had been planned) it in it's ancient history where it gained its name and reputation as a holy artifact. (Audio: Excelis Dawns)

Being able to resurect the dead it gained protection in the form of a group of zombies in the valley forests. With the help of maps from the Mother Superior It was stolen from them by the Fifth Doctor, Iris and Grayvorn with Sister Jolene.

After looking into it Grayvorn was given immortality but although he then survived a fall from Excelis mountain. (Audio: Excelis Dawns) The Mother Superior and Sister Joaline were the last surviving members of the queen's enemy and were on Excelis making sure everything went to plan. After the Mother Superior 'died' Sister Jolene learned life extension from the zombies to continue the work. (Audio: The Plague Herds of Excelis)

The Relic was found in the swamp at the foot of the mountain days later.

By 1,000 years later the Relic was an artifact in a museum, though in a secure sanctum not on display to the public.

Grayvorn, now under another name and a senior law enforcer, had thieves attempt to steal the Relic but the atempt failed—as he planned it would so he could take it to keep it safe from further theft atempts. He was called in to help in the investigation where he met the Sixth Doctor again who failed this attempt. (Audio: Excelis Rising)

Grayvorn, under yet another identity and having plunged Artaris into war, used the souls trapped in The Relic to animate his 'Meat Puppets' proto-human golems that did his bidding, his plan being to have them destroy all other life on the planet before waring with themselves and, with the Doctor's TARDIS, extend the war over the whole universe. The Seventh Doctor communed with the souls of the Mother Superior within The Relic and freed their souls, but she warned him there was more danger to come that he couldn't stop. Unable to rule Artaris Grayvorn turned the planet's orbital nuclear defence on the world's cities to destroy them, but said that The Relic would survive though The Doctor doubted this. (Audio: Excelis Decays)

When the war queen's fleet aproached Arteris the weapon began it's final countdown. The planet had been turned into a bomb with The Relic as the fuse, when the last living person on Arteris died and their soul entered The Relic it would detonate it. Jolene, now in the form of a man named Sniper, helped manipulate the last events, controling the plague-ridden animals of Artaris to kill the last of the people but in their natural form which was not immune to the virus as their native image was. Once they were dead their control of the animals ended and the killing stopped, preventing the weapon going off. (Audio: The Plague Herds of Excelis)

Abilities
The possessor was able to forcibly remove the souls from living beings. The Relic could also grant immortality (as it did with Grayvorn) and reanimate the dead.

It transfers the Mother Superior into the body of Grayvorn with him, but why is unknown.

When Grayvorn looked into it he saw the would of everyone who would ever live and die on the planet Arteis, feeling the good and wickedness and seeing a glimpse of his future. He describes it as the moment his mortal mind was lost. (AUDIO: Excelis Dawns) His immortality meant that Grayvorn never slept, though he suffered from waking dreams every few days which caused him great distress.

The Relic gave the dead of Excelis a tangible presence with the right equipment and even allowed communication with them in the form of a séance. During a séance Grayvorn demonstrated an ability to manipulate the words the dead said to suit his own ends. (Audio: Excelis Rising)

However its primary use was as a weapon component. When the last living thing (implied to be sentient life only) died on Artaris it would trigger the detonation of the planet. (Audio: The Plague Herds of Excelis)