The first one that finished the transformation was alert and moving well; which was interesting because it’s back still looked partway like a pupa! We named it Nemo and gave it its own little house made out of a medium sized container (it was ACTUALLY a mansion, by beetle standards). Pretty quick after I put it in it buried itself in the Eco Earth, which we had given it about an inch and a half of (we didn’t know what they acted like, so better to give it the option to burrow). It was tunneled right up against the side, which was cool because I got to watch Nemo do darkling beetle things.
It survived a couple days; exploring its habitat and using the little paper cup hides I had given it. It was a bummer to check on it on (roughly) day three and find it dead, but I had kept myself from getting too attached by guessing it wasn’t really going to live all that long. It’s back was the exactly the same for its entire life as a beetle; never got better or worse. Nemo was a cool little bug, and I thought I’d share about it to see if anyone else had had any experience with a beetle being deformed?
Looking back it was probably banged around or smushed too much as a mealworm or pupa, so it was probably on us that it came out that way.

Here’s what Nemo looked like, if anyone was curious.