In the far future, tiny bots injected into the body can do great good-or great harm, depending on what kind of bots they are.
A class of cybernetic prosthetics worn over the face
Augscannens are common handheld devices used by security and law enforcement agencies
There is an important pair of fraternal twins. Possibly minor dieties, sorcerers, or maybe just an important pair of nobles. One is evil and one is good. The thing is, the one who looks evil at first glance is the good one, and vice versa.