I've never seen it outside the Mabinogion, and checking records, I can't find any Creirwy births registered in the last 180 years, so it would definitely be an interesting choice. I like the Breton version Klervi better, though.
Being a Celt the list of Celtic names I like would be very long, so here's some Mabinogion names I like:
Taliesin, Gwion, Gwern,
Geraint (my uncle),
AngharadThis message was edited 10/31/2018, 2:45 PM