ORGULLO VIKINGO (how hard is it?) has very strong links to Gate13. We have a very strong friendship and 300 of OV where in Bar$alona to support Pana today. When we played eachother this year in the CL, there where several banners saying Siempre Amigos ect in the OV section.
Bar$a-Olympi / Pana-Real is one of the biggest none soccer fan rivalry's in europe. Also Olympiakos are friends with Red Star Belgrade, Roma and Atletico de Madrid. Real Madrid are friends with Lazio, Espanyol, Numancia, Boca Juniors.