I'm writing a fantasy comics and I am stuck on a particular idea. Imagine if Hell existed on our planet. Like hell is here, we simply cannot see it, because there is an invisible barrier between the two dimensions, stopping hell from overlapping with our dimension. So if this barrier broke, portals would start opening throughout the world, allowing things from the other side, hell, to get into our world. Would it be possible, even for a fantasy story?
As with many aspects of writing fantasy, the answer will almost always be "yes, of course! It's your world, you make up the rules!" Like: Can I have dragons? YES. Can I have Elves? YES. Can I have portals? YES. Can I have polydimensional beings that ordinarily consist of dissociated arrays of tentacles bilocate into our universe as large purple dragonflies? YES.
You get the point with this kind of question.
Works for sci-fi too, even though they don't always like to admit it! :)
Basically this works because you will show, through your story telling, and possibly through visual art techniques, that people in the ordinary dimension can not see or interact with people in the demonic dimension. You'll eventually show how the break-down occurs and how people cross through the portals.
Yes, it is a very common clichè.
To make it into a less common clichè, perhaps, you could have that your world is already hell, but people just don't realize it.
For travelling across dimensions that exist in the same world: https://tvtropes.org/pmwiki/pmwiki.php/Main/ShadowWalker
For a world that has gates to other dimensions: https://tvtropes.org/pmwiki/pmwiki.php/Main/PortalCrossroadWorld
Specific about Hell and its gates: https://tvtropes.org/pmwiki/pmwiki.php/Main/Hellgate
A bit late, but how I'd go about it would be to basically make it one huge DOOM parody! (mainly base it of the 2016 "reboot") Y'know the whole using the resources of literal Hell (or at least a very hellish dimension) to fuel humanity's ever growing needs for energy. Mostly just for fun, but also to explore some of the interesting implications of such a setting. OH! And of course to better distinguish your setting from DOOM's is that there is no one-man-army marine or "DOOMslayer" (in the 2016 game) to fight off the legions of Hell or there was...but he (or she) mysteriously vanished. (or something like that)