The phrase “Stay Out of the Fire” was made for Rodiafel.

Chomp – Avoid ground effects
Lava Torrent – Cast must be interrupted or DoT must be cleansed
Unstable Temperature – Spread out and avoid ground effects

Chomp – Places a fire AoE ground effect under a random player
Molten Spray – Frontal cone fire breath
Lava Torrent – Places a significant DoT on 2 random players, cast can be interrupted or DoT can be cleansed
Unstable Temperature – Signals the start of the underground phase during which time the boss will trail fire and place yellow circles on each player which must not overlap another player

To begin, make sure the entire group is inside the encounter area.  The boss will start underground with a fire circle on the ground above him. When Rodiafel is aggroed, the outer edges of the encounter area will become walls of fire.  Also, be sure to start grouped up so that Rodiafel doesn’t charge a random player out of range of the tank’s taunts.

Above Ground Phases

Once the tank has established aggro,  the remaining players should spread out behind the boss to avoid Molten Spray, a frontal cone fire breath.

Rodiafel will cast Chomp, which places a pulsing red bubble on a random player.  Within a few seconds this will become a fire AoE ground effect which should be avoided.

The boss will also cast Lava Torrent, which places a significant DoT on two random players.  Either have a designated player interrupt this cast, or have a healer cleanse the DoT right away.

Underground Phases

At 75%, 50% and 25%, Rodiafel will cast Unstable Temperature, which signals the start of the underground phase.  He will go immune and burrow quickly around underneath the encounter area, trailing red fire circles as he goes which must be avoided.  In addition, he places large yellow circles around each player that must not overlap another player or it will deal significant damage.  For both of these reasons, it is crucial the group remain spread out as far as possible during the underground phases.