Imagine you have the technology to take a person and deconstruct their body and redesign it as you wish. What improvements would be possible? As an example, is there a way to restructure muscles to make them stronger? What about bones? Would it be feasible (and beneficial) to alter eyesight to see more than one spectrum? You can opt for a drastic redesign, or simply make a few tweaks. All resources needed to upkeep these new processes are readily available. The only real limitation being that it must appear to be a normal human, and it must operate through biological means/processes. I'm not talking cyborg here.
So think better, stronger, faster.
Here is a list of some ideas that I wish to incorporate:
Increased strength/speed/endurance (and whatever changes needed to make this possible)
Stronger skeletal system
Increased awareness of surrounding. ("sense" living beings)
A way to willfully increase/decrease perception of time
How could you scientifically explain these improvements?
To help put it in context for you I will explain the events in the story. One of my characters is born with a defect that severely cripples his body. A team of doctors, along with an AI, have developed technology to help repair his condition. The way this is done is that his body is submerged in a vat of chemicals and machines and over time parts of his body are broken down and reconstructed using microscopic bio mechanical devices. During the procedure something happens to the scientists and it is up to just the AI to continue the procedure. The AI then decides to take liberties on its own and goes about "tinkering" with the patients body, resulting in the "improvements" mentioned earlier.