Raid Boss

Actually, you need to get the most HITS, not the most DAMAGE. That's what nets the finishes. Also you need to be that specific rank, but of course you already know that.

Before the raid bosses got buffed in HP, I just auto-attacked them and "kill stealed" them during one of those Summoning Urn events all while dodging their attacks. You'd best have fast weapons (daggers, dual wield if human, and possibly the Chinese armor or whatever its called for the speed boost) in order to out-hit everyone. Also, you should agree to lower your specs in case the battle lags you like hell.