I definitely can see them getting along pretty well, haha. Ophelia always rescued her fellow man back home, here she still falls into the habit. So she'd probably gently fish Rin out with her weird inky tendrils and check on her. Try to play aloof generally nasty but falls flat. Her main source of sourness isn't here so she's kind of learned to DEAL.

She'll genuinely be fascinated by it, probably offer up some help after Rin explained it to her. Be a bit macabre and wonder if this would kill her. (Since she jumped into a river in an attempted suicide and came out undead.)