Dual Wield for Berserkers: Bringing the Pain
Berserkers are the melee area-of-effect damage dealers. Because AOE skills cannot crit, the Berserker has little need for critical rating. So unlike the Blade Master who has an inherent bonus to critical rating, the Berserker cannot rely on crits for damage and relies more heavily on attack rating. Dual Wield provides them a huge bonus to attack rating especially when dual-wielding fully upgraded weapons (a Berserker wielding a pair of +3 Mithril Swords can wreck a group of enemies.) As most Berserker abilities require TP it's common to start with the skill Frenzy or consume Grilled Rainbow Fish to build TP more quickly and execute the big AOE attacks, which unlike magic AOE damage cannot be reflected back at the user (common cause of death for magic users at the higher levels.)