William Wynn Westcott (ウィリアム＝ウィン＝ウェストコット Uiriamu Uin Uesutokotto?), primarily referred to as Westcott (ウェストコット Uesutokotto?), was a Magician and one of the Three Founders of the Golden Dawn.
In the vision shown to Kamijou Touma based on Aleister Crowley's past, Westcott was described as an elderly man wearing a tailored suit with a necktie. When reproduced, he is described as being dressed like a doctor in a thick coat.
Being of an older age, Westcott followed ways of thinking which might have been considered old-fashioned at the time of the Golden Dawn. In disagreements with Mathers, he advocated traditions and the need to compromise over Mathers' desire to progress even if it meant entering areas considered heretical. Westcott was intent on maintaining his social standing and wanted his cabal to have history with an academic or royal scholar, which led him to forge a letter from Anna Sprengel to give the Golden Dawn more prestige.
In the latter half of the 19th century, William Wynn Westcott founded the Golden Dawn together with Samuel Liddell MacGregor Mathers (whom he had invited to help create the cabal) and William Robert Woodman. Wishing to give to give the new cabal prestige, Westcott forged a series of letters, the Sprengel Letters, supposedly to and from a German cabal (which supposedly had two temples) and a higher being called Anna Sprengel (authorizing the creation of a British branch), in order to have a historical and prestigious background associated with the group, supposedly the continuation of an ancient Rosicrucian line. The Isis-Urania Temple was also called #3 to reflect this background.
Unlike Mathers, who never held down a worldly job, Westcott had a job as a coroner with Scotland Yard. He was nearly fired when his association with the Golden Dawn was discovered and his superiors kept an eye on him afterwards, which meant he subsequently had to be careful when secretly attending to cabal affairs.
With Woodman retiring due to old age, control of the growing cabal was left between Mathers and Westcott. The two had conflicting views on how the cabal and magic should proceed, as the Golden Dawn worked towards the ultimate goal of discovering a unified theory to explain the truths of the world and constructing a magical work kit that brought endless possibilities for magicians. Being of an older age, Westcott advocated tradition and saw a need to compromise, while Mathers wished to see progress, even if it meant going into areas considered taboo and heretical at the time. Mathers in particular wanted his name to be the one associated with the products of the Golden Dawn's research. Eventually, the Golden Dawn eventually came to be divided between them, though neither faction had complete control over the organization as a whole.
When Mathers scouted Aleister Crowley for the Golden Dawn, Westcott was reluctant to have him join the cabal. His sentiments grew during a summoning ceremony which Aleister performed in front of the two founders, where Aleister's unconventional ideas and Mathers' intentions to use the man's talents for his own purposes were shown.
After Aleister Crowley occupied 36 Blythe Road, the Golden Dawn's most important ceremonial ground and armory, ostensibly on Mathers' orders, a furious Westcott confronted Mathers at his headquarters, together with magicians from his faction. Mathers claimed that the document was forged and it was solely Aleister's doing, but couldn't say that the document was forged with the same method which Westcott used to forge a letter from Anna Sprengel, as Westcott was in front of his subordinates and wasn't in a position to openly accept it as doing so would compromise his own position.
A war subsequently broke out between the Mathers and Westcott factions of the Golden Dawn. While battles raged in the darkness of London, Aleister Crowley took advantage to attack members of both sides and plant evidence pointing to the other side. As the war escalated, further opportunities arose and eventually an opening emerged for Aleister to take out the founders. Westcott was attacked and struck down by Aleister using Blythe Road's Treasure, Imagine Breaker, with Mathers falling not long afterwards.
At some point after his death, William Wynn Westcott was reproduced along with other members of the Golden Dawn by Coronzon, through the application of Tarot-based grimoires, as part of her anti-Crowley countermeasures.
- Main article: Coronzon Arc
During the Crowley's Hazard invasion of the United Kingdom, the reproduced Westcott appeared alongside members of the Golden Dawn led by Mathers to confront Aleister Crowley in Westminster Abbey. While the rest of the cabal hunted Aleister's group down after their escape, Westcott and Annie Horniman were assigned to playing the role of boogieman to the residents of London, to discourage them from venturing out and seeing things they weren't meant to, defeating the regrouped Amakusas along the way.
They attempted to retrieve Dion Fortune after she was caught in the Lady of the Masquerade Ball's attack on Piccadilly Circus, but were delayed due to the actions of Misaka Tabigake and then Misaka Mikoto with the Anti-Art Attachment. After failing to recover her, they encountered Fortune while investigating two distortions and when she stood against them to protect Hamazura Shiage who had picked her up instead, Westcott decided to retreat rather than risk Fortune's randomized magic and accidents disrupting his stability and quasi-immortality.
When the Golden Dawn pursued the British Royal Family on the roads between London and Edinburgh, in order to protect Mathers' true grave, Westcott acted as Imperator in their collective high-speed ceremony, and was among those who took aim at Kamijou Touma during his clash with Mathers. Eventually, when Aleister succeeded in disrupting the flow of power to the reproductions' grimoire bodies, Westcott and the others came apart and reverted to cards, with Westcott being the first to notice what was happening.
Westcott's magical ability was said to be not all that great compared to the likes of Samuel Liddell MacGregor Mathers and Aleister Crowley, however he still controlled a powerful faction in the Golden Dawn as one of its Three Founders.
This was in part due to possessing a form of quasi-immortality. He maintained this state by distorting the circulation of his life using the attraction of an extremely great being. When describing it, the recreated Mina Mathers omitted the exact details but mentioned Westcott's specialty in forging documents (having forged a letter from Anna Sprengel when creating the cabal to give it more prestige), his access to corpses as a coroner and how parchment was used to converse with demons and transfer souls. A red mass in the center of his chest apparently contained Westcott's soul. Though he never had doubts in it, believing it would never fail unless someone found the parchment he had hidden, this quasi-immortality didn't save him from death at the hands of Imagine Breaker.
In battle, in addition to the protection bestowed by his quasi-immortality, Westcott used wax, of the kind used for seals in old letters and kneaded until soft, carried in his fingers. Wax is a common material used in magic, such as in cursed dolls and the seven candles. In Westcott's case, his spell was a method of conveying willpower derived from letters (in which secrets might be sealed with wax), using a seal pressed in wax to seal power and send it to someone.
When used, the wax shone and exerted physical force along with the light. Aside from dealing physical blows and launching objects, and firing beams of light when amplified through Annie Horniman's tuning, this method could also be used to enhance Westcott's movements, such as allowing him to make a leap that seems like it would shatter his legs and reach a rooftop in a single bound.
With one usage of this spell, Westcott declared that he held a coded text and when read using the methods of Trithemius’s five books, the fragments revealed text of great power, telling his target to experience the knowledge of the Golden Dawn's beginning.
Aside from the wax, Westcott also had some form of offensive magic involving an old scroll of parchment, though it's effects were not seen due to an interruption.
Westcott possessed considerable medical experience and capabilities as a coroner of Scotland Yard. Outside of his official job, he apparently cut open bizarre corpses and examined the bodies of those who signed certain contracts on parchments. It can be assumed that Westcott has some degree of alchemical knowledge, being described by Mathers as having brought Alchemy back at the end of the 19th century.
- (To Mathers, regarding his eccentricities and lack of income) “Shut up, you jobless bum. Why are you out enjoying yourself every day when you have no income? And when you get into trouble, it draws attention to me! It’s hard enough juggling two identities without my superiors breathing down my neck!” 
- (To Mathers, regarding Aleister Crowley's unorthodox approach) "I am not saying we need to put a stop to this. I am saying even magic cabals need compromise. If we grow truly indiscriminate, we will be seen as no different from those wild partying groups." 
- The real William Wynn Westcott was a ceremonial magician and coroner who co-founded the Hermetic Order of the Golden Dawn together with Samuel Liddell MacGregor Mathers and William Robert Woodman. He was later forced to cease his public association with the group due to its growing notoriety and his position as a Crown Coroner, though he secretly continued his involvement and would later be involved in one of its successor organizations, Stella Matutina. He was also a chief of the Societas Rosicruciana in Anglia. After retiring as a coroner in 1910, Westcott emigrated to South Africa in 1918, dying in Durban in 1925.
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Shinyaku Toaru Majutsu no Index Light Novel Volume 18 Chapter 3 Part 4
- ↑ 2.0 2.1 2.2 2.3 2.4 Shinyaku Toaru Majutsu no Index Light Novel Volume 18 Chapter 3 Part 6
- ↑ 3.0 3.1 3.2 Shinyaku Toaru Majutsu no Index Light Novel Volume 18 Chapter 3 Part 9
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 Shinyaku Toaru Majutsu no Index Light Novel Volume 18 Chapter 3 Part 13
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 1 Part 3
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 4 Pat 2
- ↑ 7.0 7.1 Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 1 Part 11
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 2 Part 7
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 3 Part 1
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 20 Epilogue
- ↑ 11.0 11.1 11.2 11.3 Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 2 Part 2
- ↑ 12.0 12.1 12.2 12.3 12.4 Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 2 Part 12
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 3 Part 4
- ↑ 14.0 14.1 Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 3 Part 16
- ↑ 15.0 15.1 Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Chapter 4 Part 7
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 21 Between the Lines 2
|Samuel Liddell MacGregor Mathers||William Wynn Westcott||William Robert Woodman|
|Mina Mathers|| Dion Fortune
| Aleister Crowley