User blog comment:VedranTheII/Pretentious Diaries 1: Are my semblances worthy?/@comment-25555436-20150628140859/@comment-25555436-20150629172629

The word "unique" is subjective, and bound to be stretched. The word itself is an exageration. Each single person is "unique", and yet we can easily say we are almost all the same. Many people, despite being "unique", can have many similarities with someone else, even if they don't know each other.

The Semblances are unique in the sense that no 2 Semblances are 100% identical. While X may have Z for a Semblance, and Y does as well, their properties, the way they look, the way they work and all that, can be different, making both Semblances "unique", even if they hold similarities.

Ruby's Dash/Super Speed for example, leaves Rose Petals and fades her out of sight for a second. Someone else could have a similar Semblance, that lets them move incredibly fast in a specific direction, like Ruby's. However, that someone's Semblance doesn't leave Rose Petals and instead of fading out of sight the user leaves aftermirages. Even if they both work the same way and/or do the same thing, they are different, and as such "unique".

Unique=One-of-a-kind. But 2 kinds can be pretty similar anyway.