Murmur isn't an Elemental Lord, so please, stop. It's nothing more than flaming and it's only obstructive then anything. Never is Murmur EVER stated to be an Elemental Lord, so please, stop with that because it's Headcannon and or downplay. Murmur is stated to be a "Primal Essence" and NOT an Elemental Lord.
Therazane, the Earth Mother: At least High 6-A, Possibly 5-C, Her presence along with the other Elemental Lords is felt across the Planet. Therazane casually moved mountains and created fissures in Primordial Azeroth and was deemed a Threat to Deathwing who severely damaged Azeroth by just leaving Deepholme, comparable to the Other Elemental Lords.
Neptulion, the Tide Hunter: At least High 6-A, Possibly 5-C, Presence is all over Azeroth, along with the Other Elemental Lords, Queen Azshara saw Neptulion as a threat to the Naga and herself, Queen Azshara post-transformation with her previous form being able to hold a barrier that could hold the Multi-Continental Sundering at her Palace which was less than a few metres from the Well, comparable to the Other Elemental Lords.
Ragnaros, the Firelord: At least High 6-A, Possibly 5-C, Presence is found all around Azeroth along with the Other Elemental Lords, His mere summoning damaged the Entire region of the Burning Steps and damaging the Surrounding Regions such as Searing Gorge and the Bad Lands. Was in a constant war with Nefarian, the Son of Deathwing and one of the Major Flight leaders for the Black Dragonflight, comparable to the Other Elemental Lords.
Al'Akir, the Windlord: At least High 6-A, Possibly 5-C, Presence is found all across Azeroth along with the Other Elemental Lords, fought Ra, Thorim and Hodir, Ra of which is stated to have the power to wipe the Entirety of Life on Azeroth effortlessly. Comparable to Other Elemental Lords.
Murmur: 5-B, Possibly Higher. Stated to turn Planets into dust by Whispering, while being summoned, a Bored yawn obliterated the summoning party leaving him between summonings.
Note: Murmur is NOT an Elemental Lord, while he IS an Elemental, he is no Lord and is classified as a "
Primordial Essence of Sound. ".
Debunk: Pacifying level =/= Power, similarly, I could be saying "Because X person is weak to Y, it means they are bound to Y's level." Additionally, it does not mention the Elemental Lords, only the Elements who are much weaker than their Leaders, additionally, the extract only speaks of Draenor, not Azeroth. Frisk isn't on Asriel Dreemurr's Level and vice versa.
Archimonde, the Defiler: At least 5-B, Possibly Higher. Stated to be comparable to Kil'Jaeden but weaker, where Kil'Jaeden has been Stated to destroy the Planets that the Draenei had fled too, Archimonde's death led to the destruction of a World Tree and a massive sacrifice of the Elves Immortality to defeat him.
Kil'Jaeden, the Deceiver: At least 5-B, Possibly Higher. Stated to have Destroyed the Planets the Draenei had fled to, as well he had thought he was able to beat or challenge Sargeras and rule the Burning Legion. Stated there was a Power Struggle between Sargeras and Kil'Jaeden, however, during Legion, Kil'Jaeden stated he thought Sargeras could never be defeated.
Deathwing, the Destroyer of Worlds: At least High 6-A, Possibly higher. Had Al'Akir and Rangnaros as Lackies working under him. Damaged the Dimensions between the Planes of the Elemental Lords, bring Skywall to Azeroth as well as opening the way for Deepholme, Firelands and Abyssal Maul. Give the Title of: "Destroyer of Worlds" by Blizzard.
Illidan Stormrage, the Betrayer: Possibly 6-B with the Eye of Sargeras. His spell work was going to destroy all of Northrend and severely hurt the Elements and all of Nature on Azeroth was enough of a Threat that Nature called for his brother to Stop the spell before it was too late.
The Lich King, Arthas Menethil: At least 6-B, possibly Higher. Casually one Shot all the Heroes of Azeroth using "Fury of Frostmourne" after being severely weakened and having his heart destroyed, which was stated to have seriously hurt him on top of the New Plague being released onto him. In Order to destroy Pre-whole Lich King, the Destruction of all of Northrend was needed.
Dimensius, The All-Devouring: At least High 6-A, possibly 5-B or Higher. Stated to have destroyed Planet along with a Naaru and major technology trying to prevent it. Casually opened holes to the Void which, alone, was enough to destroy Planets without Naaru protection. Was stated to be a "fragments, shadows, the faintest of echoes" from the Voidlords. Took the Death of a Naaru to only Banish it.