I never heard of Russian band (probably because I don't really like thrash metal), but the first album of Swedish one is quite good. And Glop_Dworkin, "prog metal" sound equally silly to "folk metal" IMHO. ;-)
Just to clarify... there's folky Valkyria from Sweden and trash metal Valkyria from Russia, black metal group Valkyrja from Sweden, Valkiria - Gothic/black Metal from Italy and Valkiria, a power metal band from Chile. So not the best band name in terms of popularity.