Demons Run...

I second that

Then you're missing out

Demons Run When a Good Man Goes to War.

So you're saying that, since John is obviously a good man, that he will kill without hesitation, and that, because of that, demons will run?

You're thinking of Stockholm Syndrome.

@smitty Am I? Dammit I was so sure. I was sure it wasn't Oslo. What was Helsinkiish then? Helsinki massacre?

Theres no such thing as the Helsinki Syndrome, it is a common misnomer for Stockholm Syndrome.
https://en.m.wikipedia.org/wiki/Stockholm_syndrome
Probably as a result of its mis-atributation in the movie Die Hard. Some say it was ment as comedic effect, others like myself think it was poorly researched writing:

Gail Wallens: Author of "Hostage Terrorist, Terrorist Hostage: A Study in Duality." Dr. Hasseldorf, what can we expect in the next few hours?
Dr. Hasseldorf: Well, Gail, by this time the hostages should be going through the early stages of the Helsinki Syndrome.
Harvey Johnson: As in Helsinki, Sweden.
Dr. Hasseldorf: Finland.

I think it is just meant to illustrate it.