The Aether that's driving the Krall mad is strange, and it's affecting the Krall physically. Krall who've gone mad are reported to be...well, green, if the report's correct.
They're abnormally strong and completely insane. You should be able to handle them, though.
If you hunt Insane Dark Shamans or Insane Cursers in the Contested Expanse or the Kunpapa Outpost, you'll be able to get the [%dic:STR_DIC_I_QUEST_2694a]. Of course, I'm not certain it's green--I haven't seen it. It's definitely dangerous, though.
Go to Heiron through the rift, kill [%dic:STR_DIC_M_KrallWizardMad_40_Ae]s and [%dic:STR_DIC_M_KrallWizardMad_42_Ae]s and bring that strange Aether back here. Any questions?
Remember, the rift appears in Mahisha's Nest, southwest of Kidorun's Campsite. When you get to Heiron, take the road south from the Decayed Grove past the Black Tears Swamp, and that will take you to Kishar Village.
You'll need to go past the village and up the hill to the east. That's where you'll find the Krall who've gone mad. Keep in mind, [%dic:STR_DIC_M_KrallWizardMad_40_Ae]s and [%dic:STR_DIC_M_KrallWizardMad_42_Ae]s are known to be extremely violent, so please be careful.
Er...didn't you already tell the Brigade General that you'd go? Why would you decide not to go now? I strenuously suggest that you change your mind.
[%username], I see you've returned. What do you have to report?
You haven't been yet? Did Sorgrim not tell you the way to get there? We need this now, Daeva, not tomorrow. Get moving.
This is the dangerous Aether, is it? Hmm....
I appreciate your efforts in this matter, [%username]. Here, take this. You've earned a reward for your actions today.
Retrieve Strange Green Aether from [%dic:STR_DIC_M_KrallWizardMad_40_Ae]s and [%dic:STR_DIC_M_KrallWizardMad_42_Ae]s and bring it to [%dic:STR_DIC_N_Nerthus].
[%collectitem]The Krall have gone made from using some strange sort of Aether. Go to Heiron, kill Insane Dark Shamans and Insane Cursers, and retrieve Strange Green Aether.
Sorgrim told you that Insane Dark Shamans and Insane Cursers among the Krall in Heiron have the Aether that Nerita asked you to retrieve. You infiltrated Heiron, killed the unfortunate creatures, and brought the Strange Green Aether back to the Brigade General.