I don't know, why people are taking about having show mercy to the primitives. Think about advanced civilization and primitive civilization should not be mix. People think on Falmart that the UNDF use magic, however that's Clarke Tech third law. As for nuclear weapons? I don't know the UNDF are using fission-fusion materials or pure fusion without radiation. In some cases, they didn't have countermeasures against, magic users. Should've just abduct imperial mages and remove their brains? If they don't they should've develop a new weapon against magic users. Also it will be make sense, that the people of earth believe wizards are evil, they will eventually starts to process that they should hunt them down to extinction. Like the great jedi purge. If it not possible, I'm pretty sure among the people of earth decided to establish an anti wizard association or organization more like a pesticide that magic users are pest. If the UNDF keeps focusing about fantasy which is currently more primitive, aren't they concern what lies beyond the universe. What if there is a powerful advanced alien civilization existed hundred millions years ago before humanity existed and they are type 3 or 4 civilization.
If gate opens in phauti homeworld. The phauti would've decided to abduct imperial mages because they think their magic power are came from their brains.
To me that fantasy world are absolute alien or extraterrestrials species, doesn't matter if they are humans, besides they're primitives it's like we're talking to an arrogant conqueror cavemen.