Need help with quest can't finish it

Hello

I need help with 1 quest in Blade's Edge Mountains

Quest name is "What Came First, the Drake or the Egg?"

So this is what i must do to finish the quest http://prntscr.com/wa2zyg

Problem is i can't get Adolescent and Mature nether drake essence cuz when i brake the egg Adolescent and Mature nether drakes are green i guess it's cuz of my exalted reputation( I must kill them to get essence)...

http://prntscr.com/wa31s2
http://prntscr.com/wa32cv


This is last quest for my achievement "On the Blade's Edge" im at 85/86 http://prntscr.com/wa312b

Is there any solution?? Please help

Go in your reputation tab, click Netherwing reputation, Check the box At War. You will be able to kill them.

Thank you very much!

But what will happen with Netherwing rep after it?