Question: "Hell's Angel" is an episode in a series created by whom?

Context paragraphs:
Not Fade Away (Angel): "Not Fade Away" is the 22nd and final episode of season 5, and the series finale of the television show "Angel".  Written by series creator Joss Whedon and directed and co-written by Jeffrey Bell, it was originally broadcast on May 19, 2004 on the WB network.  In "Not Fade Away", Angel convinces his team that they must take out every member of the Circle of the Black Thorn in a defiant and probably futile stand against the Senior Partners of Wolfram & Hart.  He tells his team to make the most of what may be their last day on Earth: Gunn visits his old neighborhood; Wesley tends to the wounded Illyria; Lorne spends some time onstage; Spike performs poetry at an open mic, and Angel visits his son.  When night falls, the team divides and sets out to eliminate the members of the Black Thorn, incurring the wrath of the armies of hell.

Hell Bound (Angel): "Hell Bound" is episode 4 of season 5 in the television show "Angel", originally broadcast on the WB network.  It was the only "Angel" episode to carry a warning of graphic violence before it was first aired.  In this episode, the spirit of Pavayne – a brutal surgeon who uses magic to send the loose spirits of Wolfram & Hart to Hell in his place – torments Spike.  Fred invents a one-time use machine to make Spike corporeal, but Spike ends up pushing Pavayne into the machine to protect Fred.

Lonely Heart (Angel): "Lonely Heart" is the second episode of season one of the television show "Angel".  Written by David Fury and directed by James A. Contner, it was originally broadcast on October 12, 1999 on the WB network.  In "Lonely Heart", Angel Investigations looks into a series of killings linked to a trendy L.A. singles club.  While there, Angel (David Boreanaz) meets Kate Lockley (Elisabeth Röhm), an LAPD detective also tracking the serial killer - who believes, because of circumstantial evidence, that the murderer is Angel himself.  After discovering the murderer is actually a body-hopping demon, Angel seeks Kate's help in tracking down the bartender, now possessed by the demon, and killing him.  Kate, believing the bartender committed the murders, accepts a provisional truce with a circumspect Angel.

Angel: After the Fall: Angel: After the Fall is a comic book published by IDW Publishing.  Written by Brian Lynch and plotted with Joss Whedon, the series is a canonical continuation of the "Angel" television series, and follows the events of that show's final season.  "Angel: After the Fall" was prompted by IDW Publishing and Joss Whedon after the success of Dark Horse Comics' "Buffy the Vampire Slayer Season Eight" which is the official comic continuation of "Angel"'s mothershow, "Buffy the Vampire Slayer".  "Angel: After the Fall" sees the heroic vampire, Angel, coping with the apocalyptic aftermath of the television series after he took over and subsequently betrayed the demonic law firm, Wolfram & Hart.  The city of Los Angeles has since been sent to hell by Wolfram & Hart as a result of Angel's actions.  The series follows his attempts to rescue the people he has sworn to protect.  The first issue was released on November 21, 2007.

Supernatural (U.S. TV series): Supernatural is an American fantasy horror television series created by Eric Kripke.  It was first broadcast on September 13, 2005, on The WB, and subsequently became part of successor The CW's lineup.  Starring Jared Padalecki as Sam Winchester and Jensen Ackles as Dean Winchester, the series follows the two brothers as they hunt demons, ghosts, monsters, and other supernatural beings.  The series is produced by Warner Bros.  Television, in association with Wonderland Sound and Vision.  Along with Kripke, executive producers have been McG, Robert Singer, Phil Sgriccia, Sera Gamble, Jeremy Carver, John Shiban, Ben Edlund and Adam Glass.  Former executive producer and director Kim Manners died of lung cancer during production of the fourth season.

Battle Angel Alita: Battle Angel Alita, known in Japan as Gunnm (銃夢 , Ganmu , literally "gun dream") , is a manga series created by Yukito Kishiro in 1990 and originally published in Shueisha's "Business Jump" magazine.  Two of the nine-volume comics were adapted into two anime original video animation episodes titled "Battle Angel" for North American release by ADV Films and the UK and Australian release by Manga Entertainment.  Manga Entertainment also dubbed "Battle Angel Alita" into English.  A live-action film adaptation titled "" is scheduled for release on July 20, 2018.

Hell's Angel (Supernatural): "Hell's Angel" is the eighteenth episode of the paranormal drama television series "Supernatural"' s season 11, and the 236th overall.  The episode was written by co-executive producers Brian Buckner & Eugenie Ross-Leming and directed by executive producer Phil Sgriccia.  It was first broadcast on April 6, 2016 on The CW.  In the episode, Lucifer tries to reach Heaven in an attempt to ascend to power while Crowley states to Sam and Dean that there's a way to lock Amara away.

Angel (Buffy the Vampire Slayer): Angel is a fictional character created by Joss Whedon and David Greenwalt for the American television programs "Buffy the Vampire Slayer" and its spin-off series "Angel".  The character is portrayed by actor David Boreanaz.  As introduced in "Buffy" in 1997, Angel is a love interest for heroine Buffy Summers (Sarah Michelle Gellar), a young woman whose destiny as "the Slayer" is to fight the forces of evil, such as vampires and demons.  However, their relationship is complicated by the fact that Angel is himself a vampire cursed with remorse and a human soul, which motivates him to assist Buffy in her duties as Slayer.  The character's popularity led to the production of the spin-off "Angel", which follows the character's struggle towards redemption after moving to Los Angeles.  In addition to the two television series, the character appears in the comic book continuations of both series, as well as much other expanded universe literature.  Angel appears in the most television episodes of all the characters of both "Buffy the Vampire Slayer" and "Angel", appearing in 167 episodes (57 in "Buffy" and all 110 in "Angel").

South Park (season 10): The tenth season of "South Park", an American animated television series created by Trey Parker and Matt Stone, began airing on March 22, 2006.  The tenth season concluded after 14 episodes on November 15, 2006.  This is the first season in which Kenny does not die and the last season featuring Isaac Hayes (the voice of Chef) as Hayes quit the show following the backlash behind season nine's "Trapped in the Closet" episode.  This season also had a minor controversy when the Halloween episode "Hell on Earth 2006" depicted "The Crocodile Hunter's" Steve Irwin with a stingray lodged in his chest getting thrown out of Satan's Halloween party for not being in costume.  Episode 2 in this season is the last one with the Braniff Airlines logo.  All the episodes in this season were written and directed by Trey Parker.

Cordelia Chase: Cordelia Chase is a fictional character created by Joss Whedon for the television series "Buffy the Vampire Slayer"; she also appeared on "Buffy's" spin-off series, "Angel".  Portrayed by Charisma Carpenter, the character appears as a series regular in the first three seasons of "Buffy", before exiting the show and becoming a series regular during the first four seasons of "Angel".  The character made her last television appearance in 2004, appearing as a special guest star in "Angel"<nowiki>'</nowiki>s one hundredth episode.  Cordelia also appears in both canonical and apocryphal "Buffy" and "Angel" material such as comic books and novels.

Supporting paragraphs: Hell's Angel (Supernatural) Supernatural (U.S. TV series)
Answer: Eric Kripke