Wikia

Hydraxian Waterlords

Main leader	Duke Hydraxis
Race(s)	Water elemental
Base of operations	Azshara
Reputation
Notable reward(s)	[Eternal Quintessence] [Ocean's Breeze] [Tidal Loop]

The Hydraxian Waterlords are elementals that have made their home on the islands east of Azshara. They are sworn enemies of the armies of Ragnaros. Historically servants of the Old Gods, the four Elemental Lords served the gods with undying loyalty. The minions of Neptulon the Tidehunter were numerous and mindless. It is not yet known how Duke Hydraxis broke free of his lord's control (if indeed he has), or what his ultimate goals are, but the Water elementals are the only elementals that do not attack the mortal races with abandonment.

Located on a remote island in the far east of Azshara, Duke Hydraxis offered some quests, but they were all removed in Cataclysm. The first two required killing various elementals in Eastern Plaguelands and Silithus. Increased faction with the Waterlords opened up additional quests leading into the Molten Core. Any items obtained from the Hydraxian Waterlords, were obtained from its various quests.

Prior to patch 3.0.8, Duke Hydraxis offered the questline to obtain Aqual Quintessence used to douse the runes found near most bosses in Molten Core. This was required to summon Majordomo Executus, the penultimate boss, and, after his defeat, to summon Ragnaros himself. Since there were seven runes, any raid needed at least seven players to bring a Quintessence if they wished to finish the instance. However, after the patch, Executus automatically spawns once the other bosses have been defeated.

Duke Hydraxis could be found at the coordinates ^{[79, 73]} in Azshara. Duke Hydraxis was removed from the game as of Patch 4.0.1/Cataclysm.^{[citation needed]}

	Neutral	Rep	Notes
Mobs
	Desert Rumbler	5	Located in North-Western Silithus
	Dust Stormer	5	Located in North-Western Silithus
	Greater Obsidian Elemental	5	Located in Burning Steppes
	Lord Incendius	15	Located by Dark Iron Anvil in Blackrock Depths
	Huricanian	25	Rare Spawn in Silithus
	Pyroguard Emberseer	20	First Boss in UBRS
	Molten Giant, Ancient Core Hound, Lava Surger, and Firelord	20	Located in Molten Core
	Molten Destroyer and Lava Pack	40	Located in Molten Core
	Lucifron	100	Boss within Molten Core
	Magmadar	100	Boss within Molten Core
	Gehennas	100	Boss within Molten Core
	Garr	100	Boss within Molten Core
	Baron Geddon	100	Boss within Molten Core
	Shazzrah	100	Boss within Molten Core
	Sulfuron Harbinger	100	Boss within Molten Core
	Golemagg the Incinerator	150	Boss within Molten Core
	Ragnaros	200	Final Boss within Molten Core

Even though you can check "at war" with this faction, it is impossible to lose reputation with the Hydraxian Waterlords. Killing a Hydraxian Honor Guard will not result in any loss in reputation (nor any loot). The lowest possible reputation with the Hydraxian Waterlords is thus 0/3000 (Neutral).
As of Patch 3.0.8 returns are no longer diminished based on level.

Quests

The quests Duke Hydraxis provides are the following. There is no rep gain from turning in these quests (at least the ones listed at Neutral).

Revered - Exalted

~~Duke Hydraxis offered a self-replenishing [Aqual Quintessence] to douse the runes of Molten Core.~~
Once you've reached 20,999/21,000, you must defeat Golemagg the Incinerator or Ragnaros to gain the final point to Exalted.

Exalted

Currently there are no known rewards for 999/1000 Exalted. It would take 3-4 additional runs once reaching exalted to reach 999/1000 Exalted, as only Ragnaros and Golemagg the Incinerator will continue to give reputation points.

Notes

After patch 3.0.8, Duke Hydraxis no longer offers the Poisoned Water quest. If you have not already completed this quest, it is impossible to obtain an Aqual Quintessence. Those who already have an Aqual or Eternal Quintessence receive the achievement The Fifth Element.