For the experiment au: Are there any other side effects of the experiments other than the scars? Like illnesses or change in their biological form?
I mean, other than scars, the only one with any "abnormal" physical differences would be Z2.
Over the years of abuse, there's been quite a few parts that have needed to be replaced.
But other than that, they look like normal kids.
During this period in their life, they (and when I say "they," I mostly mean C1,) have broken many bones.
As I've said before, the long scar along C1's side was due to a near death experience. (aka, one of Jūryoku's "teaching moments" gone a little too far.)
It involved many broken ribs and other internal injuries, a couple of which weren't actually set correctly in the healing process, thanks to the sheer number of things that needed to be mended.
I mean, Aijin's pretty good at fixing the boys up, but this time. . .
. . . It was pretty bad. We'll leave it at that.
Most of the time, this doesn't bother C1 all that much physically, and he can do just about anything he was able to do before.
There are certain times where the old injury starts hurting again, usually because he over extended himself.
Depending on the severity of the overextension, he may have to sit or even lay down to keep the pain at bay.
Again, most of the time this doesn't bother him. He's no less stronger nor less capable than the others. Often times, he's the one holding them up, the rock that keeps the others steady in the storm, (pun intended :D)
This incident is also one of the main reasons C1 is more terrified of Jūryoku than the others are. And why he's so scared of dragons-
And illnesses? I'm gonna have to draw up a blank for that one. I might add something in later as the story develops, but for right now, no.
Hope this answers your questions!