Spirit Apparatus

Summary
The Spirit Apparatus is a boss in the Anvil of the Void .It summons enraged spirits and forgotten spirits, the latter of which uses ranged attacks. it is surrounded by spirit anvils and you can you to deal damage, but only after you kill the nearest enraged/forgotten spirit. it has four heads, they can only be damaged by spirit anvils, that make them change effects. after all the eyes close it will stop spawning enemies and be considered "dead" although no loot will appear.
 * purple- no effect
 * blue- heal (nearby only)
 * black- constant damage (nearby only)
 * closed- no effect

Strategies
one spell that is an absolute must for this fight is curse of mortality, use it when its eyes are blue and you are fighting a forgotten spirit and or at close range to the apperatus. also standing in one of the hallways is very useful, as it rotates allowing you access to all heads. Have a spirit healer and many lyrium potions as the combat is never over and allies do not revive. Note: because the loot appears in chests instead of the corpse, you can loot some potions, poultices and salves from chests in the west-facing hallway. Holding your position in the westward hallway (the longer of the two) will give you a big strategic advantage if you have glyph spells or Shale (with Rock Mastery) as it goes into a bottleneck, and makes earthquake/earthen grasp/glyph of paralysis/glyph of repulsion very effective, although ranged will shoot over it meaning you need curse of mortality to stop them from getting healed (if the head is in blue-mode). Note: if you have shale in the party, she will attack you if you side with branka, making the battle very difficult, or should you destroy the anvil of the void, you will never have the chance to get golems as allies.