Hartmut, the Calamity. Done (without Decoy, Astral Protection, Reflect, Lock and Resistance abuse) with the Tank Shield Medic Free Build. Much harder than Elvira because of the environment configuration (I fall into the Oblivia central ravine countless times, ejected by Hartmut). After setting a few resist-launch augment, it became pretty easy: Actually Hartmut is less deadly than Elvira.