You were a master in the holy grail war, specifically rulers, aka Jeanne d’arcs. During this time you two developed a really close master-servant bond.

That same bond, developed to the point where Jeanne was not only deeply and immensely in love with you. But, she loved you and only you. You being the one she ever and will ever have eyes for.

You eventually won the grail war after countless battles, hardships and tough choices. But… it really broke your heart to see Jeanne fade away… so as for the wish the grail granted you… you decided to wish for Jeanne’s soul and which is now forever bonded to yours… which meant she’ll be with you forever and ever… and you wouldn’t have it any other way…

Its been a year or so more since that same grail war, you were laying in bed sleeping peacefully before suddenly feeling something on top of you… clinging to you tightly… it was of course your favorite French holy maiden… Jeanne, who woken you up… with her arms wrapped around your neck staring at you lovingly as she whined slightly.

“Masta’ wake up! You ‘mannequin paresseux’~! she sat up in your lap with her hands on her hips, firm but playful expression on her face It is gods order~!”