Shaun

Shaun is the synth clone of Shaun in fallout 4. At this point, he is decades old, but does not age due to synths nature. He is an intelligent "child"? who is mentally scared from his "father", Nate (AKA the Sole Survivor) rejecting him as his son but unable to kill him. He has been locked away for years out of sight, Nate cruel response and denial of this synths existence.

Shaun therefore, is a heavily scared odd being with no place in the world, and no real love ever shown to him.