poor colt but a nice name i find

The pony left and Drill took in a deep breath. “Let’s hope that was the most scared I’m going to get tonight.”

I have a strong feeling that hope will be in vain...

“Funny, haven’t seen any Diamidians in New Canterlot before.”
“Figures, I’m the only one they let out of the Doghouse.”
Drill squinted his eyes at that. “Doghouse?”
“Little outpost they got outta town mining coal, call it trust issues.”
“Right, you know, come to think of it, I never did think about where all the Dogs we captured went after rescuing the Kirins.”

That doesn't sound good.
Like a combination of a bad events in the past and a strong potential for bad events in the future.

He’d organised them into pairs and that seemed to do the trick, with the kids learning from whoever they were assigned to and being given helpful advice. More importantly, he made sure no child was ever without an adult keeping an eye on them at all times.

That might actually be good in the long term.

“Comet Trail?” He asked.
The colt laid the book down and upon reaching eye contact with Drill visibly winced, eyes going wide with fear as he slinked back into the bed. Drill already felt tinges of guilt stab into him, like a hot knife into his back.
He raised a hoof. “Now Comet-”
“P-please don’t take my other wing!”

So much hurt in such a short sentence...

Drill paused, taken aback by the question. “Uhm, well…Is there any way I can make it up to you?”
“Give me my wing back!” He demanded.
“Comet, I’m afraid that’s not possible.”
“Then leave me alone! I’m no shooting star anymore!”

derpicdn.net/img/view/2016/5/16/1155637.jpg
Source.
Edit: The Author's Note explains why that's (currently) not an option.

Good chapter!
I enjoyed reading it.