"Yes. Ehail's doing hers, and I sent my friend who can see magic to the iceberg and my aunt to the other one. With the handy capability to teleport to the bottom of the world in case any skeptical administrators want to go for test flights. I suppose if you wanted to you could send me after them with a bigger supply of coins and the news that batches of five work, but I'd expect them to have completed all the babies by now, so it shouldn't be too urgent."
Lazarus teleports to a front-doorish part of the iceberg house. He can't be much more specific than that without knowing how the place is built.
It turns out that the most front-doorish available location is a little ledge at the mouth of a tunnel, and the tunnel leads down into the underwater - and water-filled - regions of the iceberg. Lazarus peers down it, visually and magically.
He discovers that most-of-dragons are visible to his magic-sight from quite far off. He also discovers that his magic-sight can directly perceive the thing that makes them hurt, and how far along it is.
Many of them are quite far along.
He's really not sure how to get the attention of any nearby adult shrens - calling "Excuse me?" down the tunnel into the water probably won't cut it, although he does it anyway. But since it seems he doesn't need to be shown the babies, he sees no reason not to fix them all while he's figuring out the other thing. On the off chance that a single coin can solve the whole problem at once, he picks out all eighteen of the ones he can tell are experiencing the unpleasantness of not-flying, prioritizing by how far along they seem to be, and makes his first wish to apply to as many of them as it can cover. The number turns out to be five. He fixes the next five down, and then the next, and the next, and then the last three; if there are any more babies besides those, they must not be old enough to have started hurting yet.
Now all he has to do is find someone to notify.
"Hello!" says Lazarus. "I'm from another world and I can turn shrens into dragons. I just did it to all of your babies that I could find - there were eighteen - so you should go get them and tell them they can fly now. I can do the same thing for everyone else afterward but the babies are the most important, that looks extremely uncomfortable - I can also see magic, that is how I can tell. If you want I can make you a dragon too and teleport you to the bottom of the world so you can fly around a little and verify that I'm not kidding, but it will be faster for the babies if you skip that part and I am definitely not kidding."
"Through an interdimensional hub called Milliways," he says, peering at the crystal. "I met a dragon there and then I met a shren and her magic looked very uncomfortable, yours does too, would you like to be a dragon while you're standing around calling people on your mysterious artifact? It won't take any extra time."
He's back a minute later with a purple baby - dragon. Who is tossed into the air and squawks with surprise when she successfully flies instead of falling back into his outstretched arms.
The merperson goes back and gets the other eighteen; they all swim up after him and climb onto the ice and flap their wings. Soon the air is full of purple and zinc and erythrite and amethyst and charoite babies fluttering around.
"I'm getting the rest of you now," he mentions when all the babies are in the air. "How many are there in total? If it's more than about five hundred I'm going to have to go fetch more miracles partway through, otherwise I can stay until I'm done."
Batch of five, batch of five, batch of five...
"My name's Lazarus, by the way, what's yours?"
"Well. Hi. I'm about halfway through now, I think. No one's going to complain about this afterward, are they? I suppose I could have asked everyone first, but I'm not very aquatic, and if the state of continued shrenness has any advantages I certainly can't detect them..."
"Not really," he says. "It just seemed like the obvious thing to do once I found out I could. If you have an irrepressible urge to do me favours anyway, I suppose I won't stop you, but I can't think of anything I particularly want. Oh, and there are other people at the other three houses already doing the same thing, in case you were worried about them."
"Yes! Barring some kind of terrible catastrophe where everyone involved dies, but that is extremely unlikely," he says. "And I suppose there might be a problem in - hmm - what's the usual dragon lifespan?"
"I wonder if I can do something about that," he muses. "If I can't, there might be a miracle shortage in a few thousand years."
"The kind of magic that miracles are made of comes from my world, but it is extremely difficult to make it in large enough units to miracle with - specifically, it is extremely painful to do that. So of course shrens and ex-shrens are much better at it than any of the people from my world who can. But that's only because of how you grew up, so when the last person who was a shren for the first twenty years of their life dies of old age, there won't be anyone left who can do it that easily. So I guess I should try to figure out why dragons die of old age, because I suspect it is a magic thing and I am very good at figuring out magic things."
"Hmm. And I suppose if you stockpiled it the right way, then after you ran out of miracles the next few shrens to grow up like that could get the magic to make more... but I'm sure there are still plenty of dragons who would rather not die of old age if they can help it, and it would be nice if there didn't have to be periodic gaps in miracle coverage."