"Oh! Well, in many demon languages the word for demon means something more like 'maker'."

"That makes sense, then." 

"Any idea how you mixed those up?"

"They're very similar in that language--Aklo--creator is n'k'til, and shadow is n'katl--if you give me some paper and a pen I can show you." 

Cam hands it over. "It's not likely to matter in the specific, but sure."

He writes them down. The vowels are represented in such a way that it's easy to see how one could write the one as the other by mistake. 

"Okay. The question is can you summon more daeva; and if you can, why hasn't anyone else. It's not hard. I suppose maybe other people have; 'valid daeva-summoning circle' is a conjurable parameter, but is all magic you accomplish locally by drawing on the floor likely to be harmless at small scale?"

"Oh god, no. If you were considering summoning a hornet without someone like Lucy at hand to dispose of it immediately, don't. I didn't even like doing it, but they're not as dangerous as Lucy when she's too hungry to think." 

"I'm indestructible. But yes, I'd like warning before instantiating potentially dual-purpose magic circles that might summon unfriendly critters."

"If you're indestructible and can make arbitrary objects it's probably not a disaster but if you end up with one while on a planet kill it before it can get loose. If you show me a picture of a circle to summon a demon or an angel or a fairy I can tell you whether I think it would be dangerously dual-purpose." 

"I can do that but I'm a little concerned that if summoning is somehow odd here, dismissal may be too. And the only way we could check that before risking stranding somebody here would be to dismiss me and I haven't even eradicated the malarial mosquito yet."

"Eradicated the what?" 

"The mosquitoes that transmit malaria? Do you have malaria on this Earth?"

"Yeah. That's caused by mosquitos?" 

"Parasites they carry, but it's easier to get the mosquito and they aren't an important kind of mosquito."

"That's cool. How do you eradicate them?" 

"I release a bunch of extremely attractive male mosquitoes who cannot reproduce."

Giggle. "And the pretty mosquitos aren't too dumb to fly?" 

"No, bugs and stuff about that intelligence level come out close enough to normal."

"Huh. Flying seems complicated." 

"Bugs are pretty simple. I think you can put them through enough tests to distinguish a demonic and a regular mosquito, but this is how we got malaria gone on my Earth, so they're good enough."

"Is malaria really bad? Compared to, like, polio, or typhoid, or--I don't know much about diseases, we don't get sick." 

"Those are also bad but I have to fix them with vaccines, which is a social engineering problem as opposed to a unilaterally releasing clouds of mosquitoes over the Earth problem. Malaria is arguably worst, though, just in terms of body count - some less conservative estimates suggest it is responsible for as many as half of human deaths to date."

"Whoah, really?"

"That's almost certainly an overestimate but it gives you an idea."