Isekai into Marvel/DC

John Constantine was the most well-informed person of the occult on the planet. At least he thought he was. So when the reports of attacks of hundreds of demons started coming in from New York he knew something terrible had happened. This wasn’t planned at all, someone must have made a portal to hell that the demons were flooding in from and a named demon was taking advantage of it.

He pulled out another banishment talisman and flung it at a greater demon before blasting the lesser ones with holy magic. Quick and effective as it was there were just far too many to fight that way so he had been attempting to make an anti-demon zone but the demons kept thwarting him as he did so. Any that got a whiff of his magic would come running to stop him.

He just needed a few seconds without interruption to pull it off but if he stopped fighting the civilians in the area would be torn apart as he was drawing all the demons' attention. Another wasted talisman as he broke out his third artifact to try and make some progress on making the anti-demon zone for the citizens to fall back to.

As he did so six greater demons rushed down sensing the new and interesting magic stopping his progress as he had to fight them instead of continuing. As he was about to draw out another trump card a man teleported in and cleaved the heads off two of the demons with no fanfare. The artifact which was a splintered top shard of Moses’ staff thrummed with power as he aborted his attack and used the magic to finish his circle.

The man spoke just as the anti-demon dome came into existence. “Hello Constantine, it's nice to finally meet you. Big, big fan. You might not agree but your knowledge on techno-magic really helped me out reworking other spells to work at lower circles.” Constantine looked at the man in confusion. 

He would definitely not say he was a techno mage but even when he did need to cast a techno spell he would do it in the exact opposite way the man said. He would overload the spell with higher circle mana to get it to work effectively. Constantine didn’t know that most people made one or two techno spells and that was it while he had inadvertently created more than ten by making them work with more mana. It gave the man the bare bones information on the spell that he could build off instead of starting from scratch. 

Magic hacking, magic unlocking, magic information storage, magic boundary creation and many others were far easier and cheaper to do with techno-magic. Part of the man’s anti-demon array used techno magic to draw the boundaries and store it instead of normal magic to cheapen the spell. 

He chanted a logomancy spell and Constantine felt the world shift as magic was revealed to him. The entire area was soaked in anti-demon magic. It was the creation of a gigantic demon banishment spell that didn’t seem feasible to Constantine. It would take dozens of high-rank mages to perform it once and then they’d be tapped out and the demons could just re-enter that area.

Thankfully it didn’t invade his zone otherwise once the spell went off it would interrupt his spell and the demons flooding back in would easily overwhelm the idiot who produced that giant spell. The remaining greater demon beat against the barrier Constantine produced as the spell slowly worked its way to completion. He wasn’t great at sensing ambient mana in creatures but the man's spell let him see exactly what was happening to the demon.

The demon’s own magic was turned against him as he not only banished himself but left another portion of his mana behind as a gem. The man gathered the gems from the freshly banished demons. The lessers might have been rendered into nothingness if they didn’t have enough mana to banish and pay for the spell.

Constantine’s heart stopped as he saw some of the most creative magic ever produced in the universe let alone the planet. He was overwhelmed by how simple yet effective the spell was. It was like it was cater-made to the skill level the man in front of him was at… Which was showing as nothing so he had to have an anti-scrying spell active as well.

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“I might have to steal that spell boyo. Far too effective for these normal demons to not make use of it.” I knew that Constantine would be able to use the spell himself. The biggest problem would be the boundary creation for the spell so I asked. “How would you set the boundaries of the spell? I have my own way but I’d like to hear how you’d deal with it.” 

He thought about it for a moment before saying. “I’d probably just induce a small boundary and expand with magic or an artifact until it was the size I wanted.” I had to control myself to not make pained noises as he just explained burning the power from a thousand-year artifact so he wouldn’t need to do calculations.

It was the equivalent of putting out a campfire with a swimming pool in terms of mana wastage. I guess people who were born with eight circles already didn't need to worry about things like how much a spell cost. I had already cast the spell seven times and it meant that the mana stored in the magic golems was already spent and I was using external sources like mana diamonds to make up the cost. It was getting to be a fairly expensive cost to protect the city.

As I tossed Constantine a bag with a little handful of the demons' corrupted mana I warned him. “That’s corrosive as fuck. Don’t use it unless it’s absolutely necessary or you find a good enough vessel to not injure your soul or corrupt the spell with that demonic mana.”

He tossed the bag up before retorting. “Not the first time I’ve played with demonic magics but I’ll take that into consideration.” The bag disappeared as it came down and he turned and walked towards the only large amount of demons that were left. I could feel it as well, that is where the demons were coming from.

I try to think of what is in that direction and the only thing I can think of is… The Baxter building which meant… “Fucking Reed Richards.”