One of Samurai’s katana do magic charging attack.
Consumes lot of mana, but will do high AOE damage. Samurai starts taking out mages at dark barrows with single blow from around Lv50.
Samurai also can do good shooting attack with throwing weapon and charging attack of Heavy Katana. Combined with mana regeneration and moving speed skill, he can ran while charge to avoid enemy attack, then kill enemies with single charging attack.
Prison Keep and Knights Fortress are for magic users, so I don’t expect Samurai do well at those stage.