WraithMetallica

This dragon is very quiet and enjoys dark places and stays up late at night, working directly under the Dragon Lords as a silent, loyal, private Assassin who enjoys his job.
He kills his victims in cold blood, not caring whether it's quick or painless or slow and suffering. They often bring their familiar along to quickly and efficiently remove any witnesses to the scene, which is extremely rare.
This dragon also works as an interrogation unit when they aren't assassinating under the cover of night. Nobody but their Clanmates know they are an assassin and they usually interrogate with the old-school torture methods. They chain up the individual being questioned and proceed with their usual method.

At around 2 weeks old this dragon was sold off as an all-around Assassin, meaning they would be available to ALL Dragon Lords. At first this dragon, before being sold off, was extremely caring and sweet, and very gentle even a bit shy!
After being sold off however.. They became distant and cold with everyone except their clanmates. They rarely speak nowadays and they feel barely any emotions. Again, only their clanmates can bring their old self out from their hardened exterior...