But those wings surely can’t refer to anyone but Shu—

Oh. 

This is really interesting. I never noticed that their bracelets resembled the guys’ duel disks like this. So it has to mean something that Ruri’s bracelet is similar to Yuya’s disk rather than Yuto’s. And that the wings are practically the same as on Yuya’s pendulum.

Resemble, and the colours match. Except for the last two.