Hear me out.
I don’t think he’d WANT to turn back into a semihuman. He’s already lost so much of himself, and what he looks like now IS him. He’s been like this for years, it’s a part of him, I don’t think he’s willingly go through more experimental testing just to loose himself AGAIN.
Like, yea it possible, sure, sure he’s be able to appear human again, but is that even worth it? He lost himself once, he found himself again, I doubt he’d want to loose himself again.
It’s like…
Getting rid of old cringy childhood photos. You wouldn’t do it willingly. That’s you, it was you, sure you don’t like it, but it’s still part of you, that you wouldn’t get rid of willingly.
If you could delete part of how you acted as a child, I’m sure a lot of us would be like “hell yea,” at first. But actually thinking about it, sure it was stupid and cringy, but I definitely wouldn’t be ME without it.