I think it'd be more of a one-off direct interaction and then rumors from then on- just as the isekai-ed character is a side character for sybil, so to is sybil to the stranger
earlier I planned to have an isekai-ed side character run up to a group that sybil was in and ask questions about this strange new world, with everyone else in the group acting as though they were drunk, mad, or both as they humored the poor fellow
daisy, daisy, give me your answer do. I'm half crazy over my love for you. it won't be a stylish marriage, I can't afford a carriage. but you'll look sweet upon the seat of a bicycle built for two