Gray Is Not All Colorless

One gray Troll, lonely and heartbroken because of a mistake from his tragic past, although he is constantly surrounded by love and only allows a select few to see who he really is behind his tough exterior.

The other one, bitter and cold-hearted due to the accidental faults of others and doesn't remember what true happiness felt like, being raised by the "enemy" ever since she could remember.

Who is the real beast? And how will two supposedly unhappy hearts find true happiness within each other if they are both colorless?

An AU of the first movie based off "Beauty and the Beast" with a few twists.