This quest is very easy to complete with a long-ranged team. For example, a Scout, Musketeer and Elementalist. That way it is easier to flee when Lantem unleashes his huge lightning attack and avoid it. A good strategy is to set your Scout to heal, and have your musketeer with a strong single-target shot such as Image:Head Shot.gif Head Shot, and an Elementalist with an AOE attack such as Image:Fireball.gif Fireball. This strategy makes the quest relatively simple to complete.