[@Instigator]

I'm glad to hear you're interested!
Eschaton Industries is working very hard to push the boundaries of technology and Magick, sometimes combining both. I'd say you'd be seeing things akin to the Final Fantasy series where you have (using Type-0 as an example as I'm currently playing through it and it fits better than 12/15) both Magick and technology far advanced from what we'd currently have while the state of the world stays 'modern'.
So we have things like transport airships replacing planes, cybernetic limbs and suits, single pilot mechs, etc.
Nothing too big or grand.

Yet.
In the future, however, when things get further and further in, that's very likely [s](almost guaranteed)[/s] to change.
The majority of the work [i]is[/i] handled by Eschaton Industries as they're really the only organisation with enough funds, staff and know-how to do anything. Other companies definitely exist but somehow Eschaton is really the only company who seems able to handle Magick in any capacity, hence almost all Magick-related stuff is under their watch and development. I'm certain other companies could do it, but Eschaton was the first and are clear cuts above the rest.
Not to mention there's a.. special reason, but spoilers~

The technology prior to the big bang explosion event where everyone died would be, like, about..
The 'Judgement' occurs in, say, 2016 or 2017, meaning the technology would've been modern. Cars, planes, that one head transplant..
However, you could totally have an astronaut living on one of our space stations join the story. I think it'd be pretty neat to have someone who witnessed the absolute devastation from above.
Although 20 years have passed since God appeared and then ran away, so keep that in mind in terms of age.

But being up there would be a fun perspective. It might also mean they saw something really crazy!

For the sake of simplicity I was gonna avoid delving into 'Hell' too much since the majority don't know about the things you mentioned, so originally I intended for it to be a hypothetical 'not Hell but might as well be'.
Although, really, who's to say there's not Demons out there somewhere hanging out? After all, if there's a God..

c: