Have been looking for some information about the Immerseus meta achievement, however there seems to be nothing in the encounter named "tears of the vale". Would anyone be able to shed any light on to this?
when he splits, you need to keep the corrupted blops from reaching immerseus without killing them (via stuns, roots and slows). Immersues will eventually re-appear and turns any corrupted blobs into Tears of the Vale, which you then kill 10 off
Can confirm that chain CC'ing the adds does work, the split phased lasts around 30 seconds before he automatically reforms. Any adds that are left will transform into Tears of the vale, this can be done over several transition, we done 8 on the first and then 5 on the second.