Question: What famous person does Severus Snape and Order of the Phoenix have in common?

Context articles: Alan Rickman
Potions in Harry Potter
John Nettleship
Severus Snape
Severus Snape and the Marauders
Planctus
Erotomania
Order of the Phoenix (fictional organisation)
Botticelli (game)
Wang Lin (qigong master)

Alan Sidney Patrick Rickman (21 February 1946 – 14 January 2016) was an English actor and director known for playing a variety of roles on stage and on screen.
 Rickman trained at the Royal Academy of Dramatic Art in London, and was a member of the Royal Shakespeare Company, performing in modern and classical theatre productions.
 His first big television part came in 1982, but his big break was as the Vicomte de Valmont in the stage production of "Les Liaisons Dangereuses" in 1985, for which he was nominated for a Tony Award.
 Rickman gained wider notice for his film performances as Hans Gruber in "Die Hard" and Severus Snape in the "Harry Potter" film series.
This is a list of potions used in the "Harry Potter" series.
 Many are mentioned in potions class at Hogwarts, which is taught by Severus Snape in books one to five and Horace Slughorn in books six and seven.
John Lawrence Nettleship (1 August 1939 – 12 March 2011) was a British schoolteacher who taught chemistry at Wyedean School, Gloucestershire.
 His pupils there included Joanne Rowling, whose mother worked for some time as an assistant in his department.
 He has been stated to be a major inspiration for the character of Severus Snape in Rowling's "Harry Potter" series of fantasy books.
Severus Snape is a fictional character in J. K. Rowling's "Harry Potter" series.
 An exceptionally skilful wizard, his coldly sarcastic and controlled exterior conceals deep emotions and anguish.
 A Professor at Hogwarts School of Witchcraft and Wizardry, Snape is hostile to the series' protagonist, Harry, the moment he sets foot in Snape's classroom; this hostility is rooted in Harry's resemblance to Harry's father James, who bullied and harassed Snape during their time at Hogwarts.
 Though philosophically attracted to the Dark Arts and Lord Voldemort's ideology of wizard supremacy, Snape's love for Muggle-born Lily Evans, Harry's mother, eventually compels him to defect from the Death Eaters.
 Snape becomes a double-agent on behalf of Albus Dumbledore and the Order of the Phoenix, and protects Harry throughout the series.
Severus Snape and the Marauders is a 2016 American short film written by director Justin Zagri, based on "Harry Potter" characters by J. K. Rowling.
 It officially premiered on March 1, 2016 at the Youtube channel Broad Strokes Productions.
 The fan film caught the attention of BuzzFeed, "Entertainment Weekly", "Time",
A planctus ("plaint") is a lament or dirge, a song or poem expressing grief or mourning.
 It became a popular literary form in the Middle Ages, when they were written in Latin and in the vernacular (i.e., the "planh" of the troubadours).
 The most common "planctus" is to mourn the death of a famous person, but a number of other varieties have been identified by Peter Dronke.
 The earliest known example, the "Planctus de obitu Karoli", was composed around 814, on the death of Charlemagne.
Erotomania is a type of delusional disorder where the affected person believes that another person is in love with him or her.
 This belief is usually applied to someone with higher status or a famous person, but can also be applied to a complete stranger.
 Erotomanic delusions often occur in patients with schizophrenia and other psychotic disorders, but can also occur during a manic episode in the context of bipolar I disorder.
 During an erotomanic delusion, the patient believes that a secret admirer is declaring his or her affection for the patient, often by special glances, signals, telepathy, or messages through the media.
 Usually the patient then returns the perceived affection by means of letters, phone calls, gifts, and visits to the unwitting recipient.
 Even though these advances are unexpected and often unwanted, any denial of affection by the object of this delusional love is dismissed by the patient as a ploy to conceal the forbidden love from the rest of the world.
The Order of the Phoenix is a secret organisation in the "Harry Potter" series of fiction books written by J. K. Rowling.
 Founded by Albus Dumbledore to fight Lord Voldemort and his followers, the Death Eaters, the Order lends its name to the fifth book of the series, "Harry Potter and the Order of the Phoenix".
Botticelli is a guessing game which requires the players to have a good knowledge of biographical details of famous people.
 The game has several variants, but the common theme is that one person or team thinks of a famous person, reveals their initial letter, and then answers yes/no questions to allow other players to guess the identity.
Wang Lin (; 6 May 1952 – 10 February 2017) was allegedly a Chinese qigong master.
 He first became famous for qigong in the 1990s.
 He may have met Jackie Chan、Jet Li、Suharto、Zhao Wei、Faye Wong、Ma Yun and other famous person.
 After being exposed by the "Beijing News" in July 2013, he became more famous in China.
 He fled to Hong Kong and he said he was "China's Snowden".