My personal favorite version of Power Mimicry is Empathic Mimicry. What makes this version different from traditional Power Mimicry is that it not only copies powers, but it also allows the user to form an empathic connection with the one they copy from. There are two prominent examples of this ability: Peter Petrelli from Heroes and Hope Summers from Marvel. In both of these cases, the wielder formed an emotional connection with the super humans around them, which allowed them to copy powers. In addition, their power arsenals continued to grow with each power they copied. Even though this power makes the user progressively stronger, it also enables the wielder to develop a strong sense of compassion. I am thinking of giving one of my future characters this power.