This trick was mailed to us with the following explanation:

The Vid is in german and pretty long, so i will give you a quick summary:

You have to be in Aszuna and on the Quest "Hungers End"

Hunger's End - Quest - World of Warcraft

This Method is not completely new, like in the old one, you tank Ael'Yith and Kill the Adds.
But this time you are in your own instance and nobody can interrupt you.

And now to the Exploit itself.

If you are a Druid / Warlock or Paladin you have an Ability wich deals passive DMG over Time.
For Example Druid:

skill [Brambles] and [Restoration Affinity] and you can Tank Ael'Yith forever.
The DMG from Brambles 2 Shot the Adds any Yseras Gift Heals the DMG.

All you have to do is Check here and Then if Ael'Yith is still alive, i tested on Druid and 30mins where no problem.

I didnt measure the exact EP you get but you it took 1h to 1h 30min per level for me.

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