"I have no particular advice to offer on your church since I know none of the people involved but a single church is probably not large enough in scale for the worst-case scenario to be particularly catastrophic."
"It'll be good practice," Mehitabel writes. "One thing I have considered doing is summoning all of the demons out of Hell. I have been warned that it is impossible to contain a Duke, but I doubt demons are capable of space travel unassisted and I was advised that by someone who at the time did not know that I was Christ. Can I get your expert opinion?"
"There are enough demons in Hell that I don't expect that to necessarily be an efficient use of your time, and I strongly recommend putting them on farther apart rather than closer together heavenly bodies, but if you can summon a Duke of Hell on a Jovian moon and then immediately teleport away I wouldn't naively expect that to fail. Practicing teleportation reaction time seems to be something of a prerequisite, though."
"Of course. The smaller ones can probably be safely contained without having to use an entire Jovian moon to do it, no?"
"Yes, but I would regardless be careful about leaving too many with theoretical access to each other. Pain demons in significant quantities plot."
"Yes. But shouting distance isn't that far on a planetary scale."
"If they are in fact securely bound and sufficiently likely to stay that way then 'beyond shouting distance' should reliably suffice, although do note that demons may have a longer shouting distance than humans."
The next email he sends her is a blank with an attachment that turns out to be profiles of various acquaintances of his detailing their skills, magical traits, relevant personality details, and other potentially useful tidbits.
"Thanks so much, this is a good reference to have!"
"There's some extremely salient information omitted for privacy reasons, I should warn you, but all in the category of 'things they can do,' not emotional landmines or similar that I expect you to trigger as a result of not having the information."
"I understand. Can you give me an example of something like that which you might have redacted if it were real? If there's not that many things it could be you could flip a coin to decide whether to use a real or fake example."
"Someone is a werewolf, and prefers not to let this be known because they prefer not to be viewed through the lens of the traumatic attack that turned them. That's a fake example."
There's his sister's...friend, who is a remarkably talented biology student, has a penchant for getting into trouble through seemingly random but suspiciously insistent chance and getting out of it through a combination of skill and moxy, and is relatively promiscuous but has a healthy helping of self-respect on the topic.
There's the rest of their charmingly named "B-Squad," who each have their own talents.
There are several of his and Mehitabel's fellow magicians.
There are several vampires and a few other near-humans. There are a small handful of fairies. Rannsi is on that list, actually, although he doesn't seem to know about Antarctica and does note that he hasn't seen her in centuries.
"I wanted to see Fairyland. I was six at the time so I spent a fair amount of the visit riding a unicorn around but I also visited Rannsi and her daughter."
"Perhaps I should look into re-acquainting myself with some of my old contacts. All my information on Fairyland is at least a century old by now."
"I suspect it would take more than a hundred years and the Second Coming of Christ to change that."
"I suspect there must have been some political maneuvering I wasn't expecting if Rannsi fin Vraikis vai ten Sarafel has a child. Her faction was not particularly in favor when last I was appraised."