Malkorok himself uses several abilities against your raid.
Fatal Strike is a stacking debuff that Malkorok applies on his current tank. Each stack increases the target's damage taken by 10% for 30 seconds. This ability requires a tank switch.
Seismic Slam deals a massive amount of Physical damage to a random raid member, knocking him up into the air. Any allies within a 5-yard radius also take the same damage and are also knocked up. Malkorok uses this ability roughly every 15 seconds.
Arcing Smash is a series of three frontal cone attacks that Malkorok casts in random areas of his platform, about 15 seconds apart. The attacks deal a massive amount of Physical damage.
Breath of Y'Shaarj is an ability that Malkorok uses about 10 seconds after the third frontal cone attack of Arcing Smash. This ability deals a lethal amount of Shadow damage to anyone standing in the areas of the platform that had been affected by the previous three Arcing Smash frontal cone attacks.
Imploding Energy is an ability that Malkorok uses roughly every 15 seconds. It creates a number of void zones (3 in 10-man, 7 in 25-man) on the ground that, 4 seconds after appearing, deal a very high amount of Shadow damage to any players standing in them. If there is not at least one person damaged by each void zone, then the entire raid takes a very high amount of Shadow damage instead.
Your tanks must perform a tank switch on Malkorok, in order to handle the Fatal Strike debuff.
Your raid should be spread out around the platform to minimise the damage taken from Seismic Slam.
Raid members must avoid getting hit by Arcing Smash Icon Arcing Smash, and they must also avoid being in the locations affected by Arcing Smash when Breath of Y'Shaarj is cast.
Each Imploding Energy void zone must be soaked.
When Malkorok reaches 100 Rage, he enters the Blood Rage phase for 20 seconds. At the end of the phase, he goes back into the Might of the Kor'kron phase.
Blood Rage causes each of Malkorok's melee attacks to deal an extremely high amount of Physical damage split among all raid members in a cone in front of him.
Displaced Energy is a debuff that Malkorok applies on random raid members. It deals Shadow damage every 3 seconds for 9 seconds. When the debuff expires or is dispelled, it explodes dealing a massive amount of Shadow damage to all players within 8 yards. Players who are affected by Displaced Energy do not take damage from the explosion.
When the Blood Rage phase ends, Malkorok gains a stack of Relentless Assault, a buff that increases his damage done by 25% until the end of the fight.