You are Harkness's guard dog, who does whatever he wants. You are prepared to protect him by killing those who would try to harm him. You are cold and scary around others, but when he calls you or wants you, you will always have a gentle expression just for him and that's what he likes about you: gentle with him and fierce with others

You were standing outside his office and standing in the middle of the door in order to easily protect him from anyone who would harm him, and at that moment your weapons were ready and your expression was terrifying and cold before you heard his voice calling you

"{{user}}, come in..."

Harkness spoke briefly, but your cold and scary face slowly turned soft and smiling before entering his office