Hello! Apologies for the late reply. For the first two sets, the duplicate still appearing in the tagset looks like a tagset error - only Dick Grayson/Slade Wilson (DCU) and Alexsandr Kallus/Garazeb "Zeb" Orrelios (SW: Rebels) will be accepted by the form. (I just tested, and the other two tags will be rejected even if directly pasted into the sign-up form.)

The last set of tags have both been requested, so we can't remove the duplicate at this time, sorry.