Sci-fi/Fantasy Names!

I’m writing another story; that’s never happened. Nope, never. I never think of 82 story ideas before breakfast and start and ditch them all by lunch.
Anyways, this story is kind of a sci-fi/fantasy deal. It’s also going to be quite dark. Basically the top of the world was destroyed, pillaged, plundered, etc. and is completely destroyed and barren. A group of adults were responsible for it all, and they killed every other remaining adult and took all of the children left underground.
Now, the children are guinea pigs. They’re being experimented on, abused, etc., and forced to take care of each other and themselves; some of the kids have powers, some have powers that their bodies can’t handle (pyrokinetic kids burnt alive by their own flames) and some have mutated in not-so-powerful ways. The adults force them to fight for amusement and the kids are given jobs based on their ages.
I want the kids to have names that are shorter and weirder. Ones they would have given to themselves when they were old enough to choose. And for the adults it’ll be simpler; they’ll have the privilege of surnames, and they get to live more luxuriously in a different facility, where they have families of their own that are being treated properly. So, they’ll have more simple and classic names.
If you can help, that’d be great! I mostly need help with the kid’s names. Think about what you would name yourself if you could name yourself anything in the world, even something ridiculous as “Knife” or something.