WoWDB

Overview

Ahune is a repeating two-phase fight with a soft enrage (adds summoned at ever-increasing speed). The fight tests players on their situational awareness and DPS capabilities. Since Cataclysm, the only means of accessing the boss is through the Looking For Dungeon tool or by speaking with the Midsummer-only NPC Earthen Ring Elder located wherever there is a faction or neutral capital Bonfire. A player can kill Ahune as many times as he or she desires for a chance to win loot from his Ice Chest but will only be awarded  Satchel of Chilled Goods for the first kill of the day.

Notable loot from the satchel: 

•  Ice Chip
•  Frostscythe of Lord Ahune

Notable loot from the Ice Chest (2013): 

•  Cloak of the Frigid Winds
•  Icebound Cloak
•  Shroud of Winter's Chill
•  The Frost Lord's Battle Shroud
•  The Frost Lord's War Cloak
•  Formula: Enchant Weapon - Deathfrost
•  Shards of Ahune

Phase 1

Kill spawned adds until Ahune submerges.

The tank will need to keep aggro on Ahunite Hailstone as it is an elite mob. Ahunite Hailstone has  Chilling Aura that applies a stacking DoT, and a spell interrupt. Ideally, only melee players should be affected by it.

The other add which spawns is the non-elite Ahunite Coldwave, which spawns in groups and cast  Bitter Blast. They have a small health pool but hit a bit hard on cloth-wearers. The water elementals tend to go for the healer in the group first because of healer threat. However, if there is no player on their threat list then they will go after the player closest to them - this means that DPS and healer should keep the tank between them and Ahune.

During all this, Ahune will also be casting  Ice Spear. Players need to watch their feet for the targeting visual! If a player is hit by this ability, the player will not only be hurt by frost damage but also launched high enough up in the air to suffer fall damage. This will not amuse the healer in the group. As soon as you see the visual appear, stop casting/attacking and move! The ice spear travels fast.

Avoid ice patches, as it will cause players to slip and fall - essentially a short stun.

Ranged DPS can attack Ahune if they have nothing else to do, though in this phase he only takes 25% of damage. Anyone who enters melee range of Ahune will suffer significant frost damage and be knocked back a good distance from his  Cold Slap. (Trivia: being knocked back by this ability causes  Pocket Full of Snow to appear in the player's inventory.)

Note: Ahunite Frostwind does not spawn until players repeat Phase 1. This non-elite add will pull players to its location and deal damage with its  Lightning Shield.

Phase 2

Ahune submerges and his Frozen Core becomes vulnerable for 30 seconds. Ahune will continue to cast Ice Spear but will not summon additional adds.

If a big add is up, kill it first then attack the core. If Ahunite Frostwind is still up, kill it so it won't yank players away from Ahune. Ahunite Coldwave can be ignored/dealt with via AoE and cleaving.

Once the thirty seconds are up, Ahune re-emerges. Melee players need to be ready to run out because Ahune regains his Cold Slap ability. Phase 1 starts again, this time with the additional add. Adds are summoned at an increased rate.

Note: Save Bloodlust/Heroism/Ancient Hysteria/Timewarp for the second or even third time Phase 2 occurs. If all members of the group are well geared (ilvl 520 or higher with full enchants and gems), you can probably use the +30% haste for the first submerge and kill him.