Note this contains a spoiler for Companions Quest
After earning Wuuthrad and equipping it i had my one-hand skill drop from 76 to 20 with red numbers, I doubt it is significant but it's my time marker. I also cured my werewolf blood. i cant figure out is wrong but i drank cure disease, went to a shrine (of talos: f*** the thalmor) to have diseases cured and then drank a cure poison (cause I'm clueless)