how to make boss drop.relics

[doomdoomdoom]

has anybody got the Krieg'berg Achivment?

is says something about not breaking any crystals? or using elixers?

Honestly can it be done

I think you mean the Obsidian award, it is for the very last mission against Hargkyth, not Kriegberg. To get it you have to complete the mission, not use any elixers, and not break any of the stones. I personally haven't gotten it yet. But I know several people that have. So far all of the ones I know that have this achievement did so in multiplayer (3 players all level 31).