not really sure what I'd categorize Moonsorrow as... I guess their earlier stuff has "some" overlap with powermetal, but only kinda, mostly about "iron age pagan tribe warfare/battles/life" tho. Albums I'm thinking of are "Voimasta ja Kunniasta" and "Kivenkantaja", the newer stuff starts to veer towards blackmetal and more about death and despair, even if the frame of reference stays same-ish.