Diomedes

Diomedes is a king trying to get his kingdom back. It was taken from him (or more so his family) when he was very small.  His family fled, the kingdom was divided over multiple lords and things went downhill from there (they brought back slavery, a big no in Diomedes' eyes).
When he was about 16 he decided to take back what rightfully belonged to him and started growing an army. It helped that he had inherited his family's shadow powers (more information further belong). He is 34 now. He managed to get a large part of his kingdom back already and the people are excited to have the rightful heir fighting for them.

Diomedes seems to a coldhearted person. He instills fear in his enemies and for good reason. He can be very cruel and his shadow powers are not to be messed with. He's a stern man, very serious and stoic. He does not often show emotion (other than anger that is), except with people he fully trusts. This comes down to about 3, maybe 4 people, one of them someone he has known since they were born. His very presence demands respect and he truly carries himself like a king, and a force to be reckoned with.

He inherited his family's shadow powers. These are what they sound like, the power to control shadows. In a sense this is not just a power, but more like a presence using his body as a host, waiting for the opportunity to strike and take over Diomedes' mind and body. Diomedes has great control over them, but using these powers too much will slowly make him lose control. Which basically means that they'll slowly take over his mind and, after that, his body. He has to be extremely careful. Luckily, it is pretty easy to see when he is overdoing it. His eyes slowly turn darker, until they're just entirely black. If he goes on after that, the veins going from his eyes to the side of his head will also slowly turn black (as if the shadows are under his skin). He is constantly aware of this and has trained a great deal to fully be in control and even then, it is like he is walking on a tightrope.
He often uses his powers as a form of intimidation, but he is certainly not scared of using his powers to do some real damage as well.