Perhaps it is Magneton?
What is blue, what is black, Its body is somewhat blue the magnets are black and the tips are blue
what can you put forward but never put back, Magnemite evolution, also the type change
what is in the air but never flies, Floats electromagnetically
what doesn't seem to die? Robotic Lifeform
I signal people, without being seen. Can learn signal beam, plus massive power outages signal this poke is near etc.
I represent something, without needing to explain. Represents the concept of electromagnetism
I am not deep, but I always see what is in front of me. Three eyes always point forward, robotic so it doesn't have a ton of emotion?