Do you think the font indicates WSS? Interesting that we've never seen it used with Ray. I think it's significant that the sfx appears only on her title card and not in any other situation. It's a part of her identity somehow.
The shape is like Yoru, but it's also the shape of a lot of crosses, like the one in Kuma's church and in Mariejois. Maybe it has to do with those crosses?
Could also be that she has Dracule lineage and that's the "Dracule" sfx
If Mihawk, Shuri, and Candelle are related, then I'm curious why Mihawk has so much thematic focus on sharp vision, seeing, bird imagery, etc and the other two haven't had any so far.