Mindbender (or Solace of Insanity)
Divine Star (or Cascade)
The aim of this fight is to destroy all three of Deathwing's back plates. The basic method to do this is to first destroy a Corruption to spawn an Amalgamation. Destroyed Corruptions will leave behind a hole that periodically bleed Corrupted Bloods. Destroy these bloods to leave behind a residue that can then be absorbed by the Amalgamation. After absorbing 9 blood residues, the Amalgamation becomes super heated, which enables it to explode upon death. If the explosion is close enough to the plate, it will lift it up, exposing the tendon underneath. Destroy the tendon within the next 23 seconds to destroy the entire plate, else the plate will close and the process must be repeated. Destroy all 3 plates to win the fight.
Corruptions can use this to completely immobilize the player for 30 seconds. It will release its grip once it has taken 15% damage. To avoid this always keep the final living corruption dotted up. If killed, a new Corruption will spawn, and simply repeat the process. The Amalgamation spawned by the killing however, must be dealt with using the Roll mechanic.
The mechanic that makes this fight challenging. If the player stands on either side of Deathwing's back for more than 5 seconds, it will do a Barrel Roll and the player will be flung off his back, causing instant wipe. The way to prevent being flung off during the roll is to either be gripped by a Corruption or standing on the hole left behind by the death of a Corruption. Amalgamations that are alive will also be flung off during the roll, regardless of their positions (bloods are unaffected). To prevent the roll from occurring, the player must move between the left and right sides of Deathwing's back at intervals of under 5 seconds. Be careful not to kill any corruptions just before the roll to avoid having the new corruption spawning on the hole you are currently standing, as this removes the hole under your feet and you can easily then be flung off.
Destroying the plates:
As the fight starts, basically the first step is to destroy 3 of the 4 corruptions. There will always be at least 1 corruption alive at any time, and destroying all 4 will simply cause another one to spawn on a random hole. The 3 Amalgamations spawned after destroying the 3 corruptions should then be rolled off. Then simply wait until there are 9 or more bloods spawned. Afterwards simply kill the bloods another Corruption to spawn an Amalgamation, let it absorb the bloods residues by kiting over them, and kill it next to the plate to pry it open. Simply destroy the tendon underneath to destroy the plate. Do keep in mind that the Amalgamations deal more damage as it absorbs more blood, so it's best to let it absorb them when it's about to die. Simply repeat this process for the second and final plates. Generally the second and final plates takes a lot less time to destroy since more Corruption holes open up as more plates are destroyed.