passage: (CNN) -- NBC's "Constantine" joined the growing party of comic book-based TV series with its Friday night premiere on NBC. But critics couldn't quite agree on whether it was worth staying home (or even DVRing) to catch it. Matt Ryan stars as John Constantine, a rebellious and not very likable exorcist with an affinity for trench coats and cigarettes -- at least, that's how he appears in "Hellblazer," the DC comic book upon which the show is based. To adhere to network standards, Constantine ditches his bad habit for TV, a source of contention for Hitfix.com critic Alan Sepinwall and others.
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  'Constantine,' the latest comic book based series, premiered Friday
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  Matt Ryan plays rebellious exorcist John Constantine
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  Critical response mixed
query: That's not all that worries critics about @placeholder, who introduces the real world of demons and ghouls in the premiere.
entities: Alan Sepinwall CNN Constantine DC Hellblazer Hitfix.com John Constantine Matt Ryan NBC