Rift Mob:Caretaker Arcanis  

Expert

Caretaker Arcanis is a big construct. It stands in a square shaped room with a red crystal in each corner.

The boss is tanked best just in the middle of the room. Since it randomly charges a player the healer and DPS should stand just behind it.

Three times during the fight (at 75%, 50% and 25%) one of the four crystals will be activated by the boss. As long as the crystal is active the boss is immune.

Three adds will spawn at the activated crystal. The tank quickly picks them up while the damage dealer hurry up destroying the crystal. You have only limited time before the crystal explodes, killing everyone. The time gets shorter each crystal so save your big cooldowns for the third crystal.

Once the crystal is down burn all the adds before moving back to the boss.

Master

When he activates a crystal he also summons adds. The adds and the crystal must die within the time limit he jets to the center and does the penalty AE, Morphic Explosion. This appears to be gradated, so if you are at the crystal or beyond you take less damage from the penalty. The Arcane Assistant is a caster and you may want to be sure he dies first.