This is the 12136th most frequent German word.
unsichtbarkeit
Invisibility.
In this sentence, 'Unsichtbarkeit' refers to a literal state of being invisible, which is integral to the hero's abilities.
Die Unsichtbarkeit machte den Helden unschlagbar.
The invisibility made the hero unbeatable.
Here, 'Unsichtbarkeit' is used metaphorically to describe the lack of acknowledgment of someone's contributions.
Die Unsichtbarkeit ihrer Arbeit wurde durch die Anerkennung überwunden.
The invisibility of her work was overcome through recognition.
In this case, 'Unsichtbarkeit' is discussed in a scientific context, possibly referring to invisibility as a biological phenomenon.