This trick requires Physical Shield and a number of potions. On the quest before you go to fight Jack Of Blades when he is activating that Culis Gates, there is an infinite spawn of mass units. You can use your Physical Shield on those mass spawns and never take damage. Your combat multiplier will never go down. You can get huge amount of general experience points and get your combat multiplier and use your Ages Of Will, Skill, or Strength to get a lot of experience points.