No More Tears

There is a bug with this achievement. If you kill the tears before the boss becomes attackable and they start casting, it doesn't count. You have to wait until they start casting Cry, Cry, Cry.

Once our group figured that out, it was easy.

Did this achievement today.

How to do it:

once immerseus goes in to split phase and spawn sha puddles you need to cc this puddles for the entire phase,
once the split phase is over, the remaining sha puddles you have cc'd will transform in to Tears of the Vale they have very little HP and does not need to be tanked.

Note: you do not have to kill all 10 of them in the same phase, we did it in 2 split phases.

I tried doing this on Mythic and the sha puddles would just disappear when he reformed. I had to switch to Heroic and then it worked right away.