Half the raid will get Overheated. Small red circle around them. Spread out.
Tank soak circle. Those NOT Overheated should soak with that one tank. Everyone who soaks gains Emberscar's Mark debuff, which increases damage taken by Brand of Damnation by 500%. Tank swap.
Avoid lava puddles and explosions on floor.
After second Overheated the boss will run to the centre, slam and knockback.
World in Flames - fire on platform - avoid. Those with Emberscar's Mark (tank soak) will see the debuff drop off, and also five small fire orbs (each person only sees their own) moving towards boss. Collect orbs to gain 20% damage increase per orb. Any orbs that reach the boss increases his damage by 1%.
At 100% energy, the boss ignites into flames - Heating Up - increases his damage by 10%, stacks. After the 4th time he casts World in Flames non-stop. Probable wipe.
ADDITIONAL HEROIC TACTICS:
The tank hit by Brand of Damnation will get debuff that will explode after 6 seconds .. run out.
Overheated players will have flame waves come from them. Avoid.