I think the Dublin/Neiderhein route on Sunday morning goes Dublin/Neiderhein/Manchester/Dublin. While not strictly a W pattern, it is not common to be able to spot such a routing that is not simply a straightforward rotation on between to airport pairs!
Far as I can see the NRN-DUB is operated NRN - DUB - NRN - MAN - NRN as a standard in and out pattern. It looks like that for the next month or so in timetable.