Opal was born blind but uses a spell to sense the magic within living creatures. This allows her to sense a lot than others, though she is unable to see things in the air or nonliving things.
On this day, Opal ‘sees’ a strange shape walking among the crystal ponies yet is shocked to realize no one else seems to notice it. Was it a spirit? Curious, Opal chooses to follow it.
Sombra, to no one’s surprise, was barred from entering the Crystal Empire. He didn’t mind this though. He didn’t really want to go back and be reminded of his failure. Despite that, he often visits the Empire to see his son, Olive Branch and his mother. While he knows its better to stay out of their lives, he can’t help but want to see his child.
He uses a special kind of magic unique to his kind (Umbra) to make himself invisible to the naked eye. Only those with sense outside of the natural 5 can sense him, like changelings.