In keeping with the mirror theme...
Empty Reflections
March 11, 2013
It had never occurred to him that ghosts wouldn't reflect in mirrors.
Thinking about it, there wasn't a very good reason that they should since they were hard enough to see in real life, hovering transparently about people's heads. But it had just never occurred to him that the silver surface wouldn't see them, wouldn't register when they were right in front of it.
It wasn't like he had time to spare during his fights to observe the phenomenon, but it nearly killed him (the rest of the way) when he saw his seemingly uninhabited suit posing in the mirror.
Not true in canon, but mirrors are such fun things to play with in fanfiction. :D