I agree with Lov - assemble a group and fight for it. I don't think anyone would leave it lying around unless they were collecting it. Those are worth big money.

But Awdz: I honestly have no clue. I have never fought Valkor either. This is what the wiki says:
"Dragons in group should switch fast from Valkor itself to quick banishing his appearing periodically minions as they use a lot of magic and melee debuffs typical to a Reaver mixed with undead. Primal or Life is a good choice for damage type against Valkor, to Spirit and Mind he is high resisted."
....yeah that's another page that needs updating.