Kurog Grimtotem is the sixth boss in the Vault of the Incarnates. This is a unique fight, because the boss' abilities change depending on which part of the encounter area the boss is in. The room is split into 5 sections, with the outside 4 sections being split equally into Flame, Frost, Earth, and Storm. The center section is an elemental convergence which the boss will jump to during the intermission, but he cannot be tanked in the center during the regular phases due to quickly ramping raid damage. 

He notably drops Tier Set tokens for the chest armor slot. As a wing boss, Kurog drops slightly-higher item level loot: 382 (LFR), 395 (Normal), 408 (Heroic), 421 (Mythic). 

Tactics

Phase 1

• Bring boss to outer edge of one of the sections, and move boss to new section after 50 energy.  

• Sundering Strike .. tank swap, face boss away from group.

• Frost - big white soak swirly.  

• Fire - don't stand in it.  Fire bad.

• Lightning - blue arrow spread; small blue soak circles (one player each).

• Earth - ripple/ring of earth moving outwards.  Stand on outside edge and move in as it shifts; brown swirls - don't stand in them, kill adds that spawn.

Intermission

• Ignore boss.  Two elementals spawn.  Mark one and burn down first.

• Frost elemental - interrupt Frost Binds; Freezing Tempest stand in circle around the add.

• Fire elemental - puddles of fire.  Avoid.  Try to avoid tanking this add in the section the boss is next going to be in.

• Storm elemental - targets player and does local AoE .. spread out.

• Earth elemental - large brown circles around players .. spread.  Also brown swirlies - avoid.  Tank swap Breaking Gravel.

Heroic

• Raid wide damage when changing sections.  Additional tactic per section:

• Lightning Crash (blue arrow over head) damage is shared with closest person, who CANNOT be someone else with Lightning Crash.  Gives a debuff - be aware when taking damage/soaks.

• Earth - healing absorb on some .. heal off asap.

• Fire waves .. avoid.

• Frost orbs .. avoid.