Blythe Road's Treasure

Blythe Road's Treasure (ブライスロードの秘宝) was a spiritual item kept by the Golden Dawn in the Isis-Urania Temple of the Magic cabal at 36 Blythe Road, London. It was later stolen by Aleister Crowley and later destroyed in his battle with Samuel Liddell MacGregor Mathers. It was the last known form taken by the Imagine Breaker before resurfacing as the right hand of Kamijou Touma.

Appearance
The spiritual item appeared as an arrow. As it was created from a certain saint's right hand it resembled as such, being described as that the tip branched out into five twisted prongs like a hand trying to grab at something. The shaft of the arrow as muddy-colored grave wax made from flesh and blood, the feathers made from leather, and the arrowhead made out of bone.

Principles
Blythe Road's Treasure was made out of the right hand of a saint, preserved and turned into a spiritual item. It appeared as an arrow but is thrown like a spear instead. The spiritual item's specialty was to exorcise an uncontrolled being beyond the magic circle after a failed summoning. In Aleister's meeting with Allan Bennett, he implies that the spiritual item can be used to exorcise the effects created by the sparks and collisions made by the phases of the world due to people using magic, hence why Westcott and Mathers weren't bothered by its effects when performing magic. As it is still the Imagine Breaker, it can negate magic as shown when Aleister used it against Mathers' magic attacks.

When Aleister used it as a weapon against Westcott, his quasi-immortality was negated by the power of the Imagine Breaker and the physical arrow simply ripped out his heart.

Background
Prior to 1900, the spiritual item was already in the possession of Golden Dawn, and was kept in the Isis-Urania Temple, the cabal's armory. Indeed, the primary function of the spiritual item as a tool for exorcism was referenced by Westcott when Mathers and Aleister Crowley summoned a demon. The spiritual item would not be used however as the demon was trapped inside the magic circle, showing Aleister's prowess in magic, much to Mather's enthusiasm as he is able to show off to Westcott through his apprentice.

After Aleister Crowley discovered that his future daughter will die of illness because of the effects of the sparks and collision made by the phases of the world due to people using magic, part of his plan to destroy the Golden Dawn was to steal the spiritual item. After stealing blood from Mathers, he raids the Isis-Urania Temple in Blythe Road and steals the treasure there, using Mather's blood to frame him as the one ordering Aleister to attack Blythe Road. This would later cause a rift and then a war between Mathers and Westcott's faction, exacerbated by Aleister killing both factions' magicians and pinning the blame on their deaths on whichever faction the magician he murdered opposed.

Aleister would later use the spiritual item on Westcott and Mathers, the latter would prove to be its undoing as after attacking Mathers' arm it exploded, destroying the spiritual item.

Trivia

 * The basis of the treasure as a preserved right hand of a saint may be a reference to the Holy Dexter or Holy Right of, whose right hand had been removed from his body after his death and became a relic, said to have miraculous properties.