Instructions
Begin the fight by having the tank run up to him. Everyone else in the group should run with the tank and stand as close to Loken as possible. Melee should go behind Loken to avoid parries and blocks. Loken casts a spell that continuously deals damage damage to the group. The farther away group members are, the more damage they take.
Run away from Loken immediately when he begins to cast Lightning Nova. Lightning shooting from Loken and a blue spell graphic on the ground indicates when the spell is about to cast. Even the tank should run away, due to the damage from the spell. Run back to Loken immediately after he casts the spell.
Instruct all other players to look at their debuffs. If a player sees the "Arc Lightning" debuff, he must run away from the group. Instruct the player to stand on the stairs to avoid spreading the debuff throughout the group. After the debuff wears off, the player can rejoin the group.
Continue to fight Loken by grouping together until he casts Lightning Nova and having the player with Arc Lightning run away. After a few cycles, Loken should die.