Cuthbert Sinclair or Magnus was a rogue Man of Letters and a very powerful magic user.
Cuthbert was the former "Master of Spells" of the Men of Letters, and served as Henry Winchester's tutor and friend. He was the one responsible for creating the warding that kept the Men of Letters bunker safe. He proposed multiple measures and encouraged the Men of Letters to use their knowledge to destroy evil. However, the Men of Letters refused his proposals and eventually kicked Cuthbert out in 1956. Afterwards, Henry visited him several times to try to convince him to change and come back. Cuthbert however refused. Somewhere along the line, he made himself an invisible and intangible mansion, which was only accessible by magic, and became a collector of rare supernatural antiquities, including monsters (which he placed in a zoo inside his manor).
In 2014, now calling himself Magnus (after the Men of Letters code name for when they went incognito) he acquired the First Blade for his collection and later met up with Henry's grandsons Sam and Dean Winchester, who were hunting for the blade and claimed they wanted to talk to him about being a Man of Letters. Letting them in, he had them fight some of his monsters as a test. After they succeed, the brothers inform him of Abaddon and tried to convince Magnus to lend them the blade. However, Magnus was more interested in discovering Dean, who possessed the Mark of Cain. He banished Sam, and kidnapped Dean to add him to his collection. He tried to convince Dean to agree, and when that failed, he began using his magic to brainwash him, as well as experimenting with the effects of letting Dean hold the First Blade. Using the spell from his premise, Sam broke back in, but Magnus captured him with the help of a shapeshifter from his zoo. Realizing he could control Dean through his brother, Magnus began to torture Sam with a knife. However, Crowley (who had followed Sam in) freed Dean, who took the First Blade and beheaded Magnus.
While looking for information on a codex that could decode the Book of the Damned, Sam finds out that Magnus (back when he still was a Man of Letters) hid it in the Werther Box, a magical invention of his own creation that causes hallucinations to make the person under its influence to commit suicide. Sam listens to the tape of the meeting where Magnus was expelled, in which he defends his actions in creating the Box because he feels the codex is too dangerous to allow the Grand Coven to recover. However, the other Men of Letters are not impressed as the Box caused two of their high-esteemed fellow members to kill themselves with its failsafe system. Magnus tells the other Men that they should be out fighting evil with the knowledge granted to them, not "mouldering in the stacks" of the Order's Bunker like librarians. Markham gives Magnus a chance at leniency if he tells them how to break the warding spell on the Box, but he refuses and is escorted out though he tells them that Martinez, one of the mentioned two members who died trying to disarm the Box was on the right track, though he doubts the rest of the Men have the courage to try. Rather than try, like Magnus expected, Markham orders the Box guarded and not to be attempted to be opened again, left where it is in the house of the St. Louis chapter. However, when Abaddon destroys the Men of Letters, the Box was forgotten and no longer guarded, until the house is bought by Suzie's father, who attempts to open it and causes all her family to commit suicide.
In the present, Sam and Dean attempt to disarm the Box. Sam's attempt at using a spell given by Rowena fails and he, Suzie and Dean fall under the Box's influence. Suzie kills herself and Dean falls into a catatonic state where he imagines he is in Purgatory where Benny Lafitte encourages him to kill himself so he can stop Sam and Castiel from having to do it when he falls under the influence of the Mark of Cain fully. Sam is apparently saved from a hallucination of Suzie by Rowena, but it is just another of the Box's hallucinations. Sam eventually discovers that Magnus designed the Box so that only the blood of a Man of Letters or a Legacy could break the spell, but that it needs all of their blood. Sam attempts to sacrifice himself to stop Magnus' creation and save Dean, but Dean breaks free of the spell and stops Sam, adding his own blood to the mix. Sam and Dean's blood disarms the failsafe spell and they are able to open the Box and get the codex. Dean later utterly destroys what's left of the Box just to be sure.
Powers and AbilitiesEdit
Magnus was incredibly powerful and skilled with sorcery, deemed a Spell Master after he was initiated into the Men of Letters. He was an extremely cunning strategist and a sadist, who worked wonderfully when on the spot.
- Magic - Magnus was incredibly skilled at magic and spell casting, using it for a variety of purposes, so much it was him who told the brothers there was "a spell for damn near everything":
- Immortality - He knew magic that could extend his life and youth, thus appearing in his late thirties despite being over ninety.
- Portal Creation - He was able to use magic to open a portal in and out of his heavily-warded mansion for himself and visitors.
- Apporting - Magnus used a spell to banish Sam Winchester from his home after deeming he didn't need him anymore.
- Thermokinesis - Magnus used a spell to cause Dean's blade to heat up so he could disarm him.
- Mind Control - Magnus used a spell to begin brainwashing Dean, robbing him of his free will. However, it was a long process and he admitted it would take lots of sessions before he fully got Dean under his control.
- Warding - He has used his knowledge in warding and protection magic intensively. He was the one who was responsible for creating the ward that kept the Men of Letters bunker safe. The ward, the apex of his skill, rendered the Bunker unbreakable for all intents and purposes, and inaccessible to all but Men of Letters. He also created the Werther Box, a magically imbued vault meant to contain powerful artifacts, by casting a powerful mind altering enchantment upon it, giving it a 98% chance of inducing anyone who tampered with it to commit suicide. Only the Mark of Cain, the very first curse, was able to overcome it.
- Despite his claims that the Men of Letters never actually do anything, several instances have been documented where they took action. Such actions include Henry Winchester and Josie Sands being sent to investigate the activities of Abaddon in Milton, Ohio as a field test of their abilities before initiation; they also used their political power in the Middle Ages to destroy the Grand Coven and to kill the witch Nadia. They also allied themselves to and helped out the Judah Initiative against the Thule Society during World War II. Likewise there are several cases of them investigating and helping out those troubled by the supernatural. As Sinclair proved to be insane, it is safe to say his claims carry little merit.
- Cuthbert Sinclair is Dean Winchester's first kill with the First Blade.
- Actor Kavan Smith previously portrayed a civilian who was murdered by Doc Benton in the Season 3 episode "Time Is On My Side".
- Cuthbert is the first collector of supernatural articles seen in the series. The second was Ramiel and the third was Luther Shrike.