I love Welsh names! I think they can be used by anyone, but a very Welsh name with a very Spanish/Muslim/Russian... surname could be ridiculous ->
Gwendolen Mohammed,
Owen Corleone... lol
My favs:
AngharadAnwenBlodwenBronwenCeinwenCeridwenDilysEilinel
Eilonwy
EilunedEilwenEthelwyn
GwynethHefinaLlewellaLlewelynMargedNerysOlwenOwenOwenaRhiannonRhosynSerenSiana