Human genetic engineering. I’m sure governments are already doing this, because the technology is already here.

You could create super soldiers or very intelligent people. You could then copy them in cloning vats and have an army of people you could shape and mold to your will.

Could experiment with all sorts of stuff. For example they’ve put biiluminescent genes from certain fish into frogs to make glowing frogs. Now imagine giving humans the raw power of chimps. Or the ability to see UV light like birds. Or venomous spit. Or the power to smell like dogs.

Realistically would just end up a developmentally stunted invalid. There was an example from some book, I don’t remember which, where there was a SE Asian woman who lived with her family and had a baby.

The family was ashamed, so they forced the girl to keep the baby by itself in the attic. She would go to work most of the day, and come back to take care of it when home. That was the total extent of interaction and stimulation the baby got. It ended up being severely stunted and never learned to talk.

Essentially young children need human interaction which includes warmth and constant validation, caring for, etc

If you interrupt that in any way, you end up with a feral child who is permanently stunted.