Dark Elf Corrupter never spawned
 

But I got his quest text,I do not think I did the turn in wrong

Name is Leakingwood

Were you at their spawn point or were you waiting near the Druids?

I was standing next to Druids, I did not even get the dark elves on track

The bug is that they will not run to the Druids. The quest will still work if you run to their initial spawn point up on the mountain. They shout when they spawn, and if you're a Druid they spawn too far away to be tracked. This should be fixed next update. At this point in the quest it may be easier to start over.

to circumvent temporarily, run up to the top of the hill north of the druids and track from there, they will be to the east.

Tested today, if you head to the mountain at -1500 -1000, they will spawn at the base of the hill (you'll see them on track).

You can harmony the two shadow knights and kill the necro on its own.