Quick Reflexes

Best is to do this one solo. In a group there will be a lot more of these Tendrils and Manifestations and there always be someone getting hit with Tendrils

For the Tendrils, just step out of the green circle. And pull enemies out of the water, as that green circle is hard to see in the water.

For the Manifestations, keep one of your interrupts or stuns available always. Never use them on anything else. These manifestations spirits are called: Twilight Voidcaller. Their cast takes 12 seconds that you have to interrupt or step out of that big circle. Easiest way is to make a macro if you use a char with ranged interrupts or stuns:

/tar Twilight Voidcaller
/cast *name of your ranged interrupt/stun*

This achievement is considerably easier on the Zul'Aman Broken Throne site, since it doesn't have water to hide the green circles. Stay off of stairs as much as possible though, since those can hide the circles.

Pets do NOT affect this achievement for those worried. My pet got trapped dozens of times. I got hit once as it was in the water and the ogre spawned at the same time so I couldnt see the roots until it was too late lol.