Barrage

How do these Christians produce shields?
Can it be replicated and produced on a personal level with cartridges or perhaps a fuel source?
Does virgin blood act as a fuel source, how much blood does it take to fuel a generator for a minute, or does the drift wood cross have some significance, perhaps mixing the two?

@Devalut no blood, at least outside of the body. Seems more like a mentally induced shield and for some reason you have to stand with your back at the evil in question and on your knees with our head and eyes in your palms.

Would it be possible to make this portable?
Make a "condensed" pious donor with a camera that constantly faces the direction of the attackers keeping the subject back to it at all times?

much akin to curse cartridges:

@Devalut I guess you could use mirrors.

Or maybe he could do it Jimmy Olsen - Wikipedia if he'd exist.