there's a lot of potential there, and a lot of appealing aspects - major height and size difference, human/immortal, wolf/bunny, pastel lolita/punk goth.... oh even their fighting styles contrast! wriothesley is a boxer, so he's close range while sige uses a bow and gun, making her long range. there's also their other contrast of the desire to trust vs the desire to be trusted

but i think what made me actually cement it as an otp was the office scene in the archon quest where sigewinne tranquilizes lyney. wriothesley barely moved when lyney lunged at him, not even to just stop him, like he /trusted/ sigewinne to 1) get there on time to stop any violence from happening and 2) be a very precise shot (this indicates to me that he has seen her in action many times before to already trust in this)

and the conversation that followed indicated to me an equal relationship despite wrio being the boss. he trusts her, she trusts him, but doesn't always approve of his methods and admonishes him for it, which made him take a step back and go yeah ok let me explain.

if he is the king, then she is his queen. if he is the head, then she is the neck that can turn the head anyway way she wants.

they have a lot of trust and respect for each other, something that has seemingly been built up over the years since wriothesley took office, but had it's seeds planted since he was a prisoner and her patient.

i'm sorry, i'm not the most articulate bc i would love to give a full proper analysis on that office confrontation scene and what it says about wriosige and why it made me fall in love with it in precise words, but this is the best i can explain it.