They did the modification on all 4 kids first and it was a success, its just after Sora took the drug that changed only Sanji..
Sanji can still have his modified genes dormant so he could grow up as a normal human being with feelings.. Another scientist said Sanji can't be just a normal human and asking Judge to wait more time for his development..
That doesn't make sense because Niji can use invisibility without his suit and he's not Stealth Blue..
Another thing, maybe its just an error but if Sanji was meant to be stealth black why they gave him a yellow shirt from the get go?
Also Sanji eyebrows are like his siblings but in reverse, he's obviously modified.. Oda hides Judge's eyebrows because they must be normal..
Its not likely that Sora is from that clan because Queen said its not as if you're from the Lunaria clan, which means Queen knows from Sanji's appearance that he's not a Lunarian and why King's body and face is hidden, he must have a distinctive look like the Fishmen or the Minks that's easily recognizable.. Then, altering genes is one thing, but for the drug to redo a modification of their genes is another, it takes more than drinking something to modify genes through scientific process.. Unless its a devil fruit or straight magic
Or it was simply a good segway to throw in King's race for the readers because they both use fire, nothing more nothing less..
I will do a list :
1. Sora went through the surgery to give the kids special powers, then she took the drugs to disable this BEFORE they were born but only sanji came as the normal one.
2. Where did niji used invisibility ? Gotta have to explain to me cause i didnt see it ever
3.You could go the other way with it you know, maybe everyone who got lunarian dna have these kind of eyebrows ? or maybe it does mean he was modified but because its the other way around just proves more he is different then his brothers, plus sanji colors were always black and yallow, the raid suit is black.....
4.Dude there is must be a reason a lot of people thinking about it, if that was a bunch of bullshit not many people would agree and make threads about, oh and a drug that can nullify superpowers like devil fruit is normal ? If thats possible then everything is preety much and i think vegapunk might be behind this.its obvious that sanji does not have the appearance of a lunarian because i think they wings but if sanji is going to "transform" then maybe he could get wings, but still, queen went out of his way to mention the only "humans" who can burst into flames are lunarians.
Sanji got his emotions, he got powers that his father didn't even comment about, he is getting hinted to be at least connected to lunarian by being able to combast into flames plus his powers work on his EMOTIONS, something that his modified brothers certainly do not have.
Listen, i am not saying sora is 100% lunarian, im saying there is a possibility but the thing that most likely happens imo is because of drug she took. thats it sorry if this is messy to read.