Lost Drengr are human boss enemies. They are powerful vikings that want to duel you. Speak to them and then fight them. After the duel is over, talk to them again and then confirm the kill. Lost Drengr count as MYSTERIES. After killing them all, you will receive the quest "The Lost Drengir of Ragnar Lothbrok".
A drengr is a glorious and honorable warrior, one willing to go to the ends of the earth seeking righteous glory. The term can be literally translated as "badass". These were the elite and would have stood by Ragnar no matter the circumstance. Now they are somewhat lost, but still crave Valhalla.
