Hresvelgr asked you to go to Dark Poeta and kill Brigade General Anuhart to seize the Concentrated Vitality. He didn't know where Anuhart was to be found so you should look in Dark Poeta first. You learned that Anuhart will only come to Dark Poeta when you find the Balaur Operation Orders and destroy the Telepathy Controller as well as the Power Generators. After you did this, Brigade General Anuhart appeared. You eliminated him and received the Concentrated Vitality. Hresvelgr was relieved that you found the item that was so important for the future of Asmodae.