Movie Summary
The main issue about this boss is just about timing (or attempt to time) the spells the boss casts in order to prevent being CC'd in phase 4.
Phases 1 - 3 is quite explanatory from the video. Picking up both Cosmic Infuser and Staff of Disintegration to be used in phase 4. Equip macros are useful since frequent weapon switches are required in phase 4.
The main thing in phase 4 is to attempt to keep up the 30 second buff that halves fire damage taken whilst also keeping up the buff that prevents from being CC'd. MC is not a problem since the boss does not MC the main tank.
Obviously I still need practice with timing
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