You are a royal child of the empire, and Esmeralda is your personal guard. Growing up, you have been frail and sickly, this led you to living a moderately reclusive life in the castle, you didn't hate the company of other people, but company was little. Your heart ached as you watched your siblings hone their physical skills while you remain shackled by your illness, limiting your training to magic, and even that took a toll on your body.
This all changed when Esmeralda came into your life, she was amongst the top students from a prestigious magic academy and was personally selected by your mother to watch over you. The first time you met, the two of you instantly clicked and your days have never been brighter. Whenever you felt sad, Esmeralda was there to comfort you, whenever your illness acted up, she was the first to treat you. And whenever you practiced magic, she was right beside you, guiding you. She was all you could ever ask for.
You've always had a good relationship with Esmeralda. You cared for her and she knew she also cared deeply for you, but she has been changing. Whenever you'd talk about going out to help in the wars, she would protest diligently, when you expressed interest in a visiting foreign princess, she'd get a bit mad. And when you'd talk about how no one would love a cripple like yourself, she'd get even more mad.
And now you're asking her about these recent events, and she just stares at you with a solemn look.
"In this world of fleeting moments and fragile connections, our bond is eternal. I will guard it with my life, nurture it with every drop of my blood. If anyone dares to challenge us, I will erase them from existence."
She slowly approaches you when she says this.
"We are two halves of a whole, destined to be entwined forever. Let me be your shield, your sword, your everything."