Question: What television network hosted the show in which Matt Ryan played the character John Constantine?

Context paragraphs:
Hellblazer: Hellblazer (also known as John Constantine, Hellblazer) is an American contemporary horror comic book series, originally published by DC Comics, and subsequently by the Vertigo imprint since March 1993 when the imprint was introduced.  Its central character is the streetwise magician John Constantine, who was created by Alan Moore and Stephen R. Bissette, and first appeared as a supporting character in "The Saga of the Swamp Thing" #37 (June 1985), during that creative team's run on that title.  "Hellblazer" had been published continuously since January 1988, and was Vertigo's longest running title, the only remaining publication from the imprint's launch.  In 2013, the series concluded with issue 300, and has been replaced by a DC Universe title, "Constantine".  It was then relaunched in 2016 with the title "The Hellblazer" as part of "DC Universe Rebirth", restoring the character to his original cast, tone and setting.  Well known for its political and social commentary, the series has spawned a film adaptation, television show, novels, and multiple spin-offs and crossovers.

Missing Persons Unit: Missing Person's Unit is an Australian television documentary series on the Nine Network hosted by actor and personality Steve Bastoni.  The show documents people who have gone missing in Australia and the police who investigate their cases.  The show was hosted for its first three years by Mike Munro before he moved to the Seven Network.

The Rachel Maddow Show (radio program): The Rachel Maddow Show was a weekday radio show on the Air America Radio network hosted by Rachel Maddow.  The show featured news items read by Maddow and her commentary on each of them as well as interview segments with politicians, newsmakers and pundits.  Guests included presidential candidate John Edwards, author Eric Alterman, reporters from "The Nation" magazine and commentators from The Center for American Progress.  Beginning September 8, 2008, she also debuted a TV version of the show on MSNBC of the same name with different content.  Early in 2009 the show was moved to the 5AM timeslot and consisted almost entirely of the audio from the previous nights MSNBC broadcast of Maddow's television show.  On January 21, 2010, Air America Radio ceased programming citing economic difficulties.

Magic Shadows: Magic Shadows was a 30-min Canadian television series produced by the TVOntario public television network hosted by Elwy Yost that ran on weekday evenings from 1974 to the mid 1980s.

Celebrity Playtime: Celebrity Playtime is a Filipino television game show on ABS-CBN network hosted by Luis Manzano.  Prior to Manzano, the show was hosted by Billy Crawford before dropping due to some issues regarding the time-slot.  it premiered on ABS-CBN on September 26, 2015 until it ended on April 3, 2016.  The show features celebrities playing house party games.  It originally aired on Saturdays at 6:00 PM (PST), but on November 14, 2015, it was moved to 10:30 PM to give way for Dance Kids, however the following week, it traded timeslots with Failon Ngayon.  On January 23, 2016, it started airing on Sundays replacing Luv U.

EGN Australia: EGN (EFTel Games Network) was the online computer games network hosted by the Internet service provider, EFTel.  EGN was first established in May 2004, when John Ryan registered the business name: "EGN Australia".

Constantine (TV series): Constantine is an American television series developed by Daniel Cerone and David S. Goyer for NBC, featuring the DC Comics character John Constantine.  Matt Ryan stars as Constantine, a British exorcist and occult detective who actively hunts supernatural entities.  The series aired from October 24, 2014 to February 13, 2015, over 13 episodes.  On May 8, 2015, NBC canceled "Constantine" after only one season due to poor ratings.  Ryan reprised the role in a guest appearance in the fourth season of The CW series "Arrow", set within the Arrowverse, and it was announced in January 2017 that he would voice the character in an animated web series on The CW Seed later that year.

Matt Ryan (actor): Matt Ryan (born Matthew Darren Evans; 11 April 1981) is a Welsh actor from Swansea, best known as Edward Kenway in the Ubisoft video game "" and John Constantine in the NBC series "Constantine" and The CW series "Arrow", as well as voicing the character in the 2017 film "Justice League Dark".

Hellblazer Special: Bad Blood: Hellblazer Special: Bad Blood was a comic book limited series published by the Vertigo imprint of DC Comics in 2000.  It was written by Jamie Delano and illustrated by Philip Bond, and features the character John Constantine, albeit several decades after most of his series continuity.

The Horrorist (comics): The Horrorist was an occult and horror-themed comic book limited series written by Jamie Delano, with art by David Lloyd, published by the DC Comics imprint Vertigo.  It was a spin-off of Vertigo's popular "Hellblazer" series and features the character John Constantine.  The book consisted of two 52-page issues without advertisements, published in December 1995 and January 1996 respectively.

Supporting paragraphs: Matt Ryan (actor) Constantine (TV series)
Answer: NBC