Once you know what to do this is a fairly simple and quick achievement.
Video guide:Text guide:A huge thanks goes to Dr Doppelklick for explaining something I did not realize when I wrote my previous guide, this simplifies the task big time!
When you start a new character you will start in Gorgon Pass with Katarina, first thing to do is to press
and go over to skills, go to your Shoot skill (In the Occult Hunter section) then press
on one of the three smaller circle above it. Go over the middle circle (Tar shot) and press
3 times to switch the number to 0. Now press
to finish the combo.
Continue through the level as you would normally until you level up, when you level up put the character points into dexterity, one skill point into the Shoot skill and one into the Ghostly Mirage trick.
Now continue on once again until you get to the large clearing just past the shrine (noticeably larger on the minimap) inch to the right a little at a time to get the wolves attention in here then bring them back to the left abit to kill them so you do not activate the Domovoi spawn.
Once you clear out the group of 10-15 wolves you should go into the menu, go to the companion tab and press
to switch the far left panel to the behaviour settings, change melee to ranged and defend to assist. Now go into the skills tab, go to the Shoot skill and press
on the 3 smaller circles again, while over top the middle circle (Tar shot) press
3 times so it shows the number 3, press
and close the menus.
Equip the gun if it is not equipped already.
Now you will walk to the right and when Katarina says "Look a Domovoy" you should see a creature running from the top of the screen to the bottom, quickly press
to use Ghostly Mirage, then press
to activate rage now you can shoot the Domovoy with
and hold it to keep shooting. You may have to reposition yourself to keep hitting him.
Once the Domovoy has jumped off the cliff pick up all that sweet loot (including gold piles) and you should unlock the achievement.
Credit for the tip of not constantly depleting your rage goes to Dr DoppelklickZavistic and Born Knight 74 have confirmed that this achievement is also cumulative in case you do not get 20 on your first try, however some people have also said the achievement was NOT cumulative for them**Playing on my girlfriends account I did get the achievement to 80% on my first attempt, and then hit 100% on a second character picking up only a minimal amount of loot, however that being said I feel that the counting is off. When I got 80% I only picked up a few pieces of loot/gold, and when I went from 80% to 100% I could only see 1 single pile of gold get picked up by my character which obviously does not make sense. I would say if it does not unlock on your first or second try just keep trying. but personally and as people have said in the comments it
should work.**