I have a little over 100 relay battles in
I've never seen: Amber, Saphir, Bunet, Pandreo,
I've rarely seen (fewer than five times I'd say): Jade, Boucheron, Fogado, Rosado, Goldmary, Citrinne, Lindon, Clanne, Vander (once, I was surprised as all hell)
I've seen Etie way more than I expected, and the rest are fairly popular