So in my current playthrough of Skyrim, my vampire dark elf married Vilkas
So I get home (the home site you buy at Falkreath, not an in-city house), bandits attack me, I find a letter on them saying Vilkas was kidnapped.
I am baffled, as he's a damn werewolf, but start my journey to save him. Have to walk to the cave he was taken to as it or places near it weren't discovered yet.
By the time I get close enough to see the cave, the mission claims to be completed. I still went through and killed all the bandits. And ya, he wasn't in there. So I get back home, and he's there.
But he's all messed up now. All bugged.
He walks backwards a lot.
Sometimes he'll be doing this weird walking-in-place where he's moving kinda weird (rolling his shoulders, legs moving like he's walking backwards, shaking his head left and right).
If he's in bed, I can't talk him up like any other characters. In fact, sometimes he'll just be laying there with his eyes open. And every time, he never gets out of bed unless I travel a bit a ways from my house and wait.
He hardly goes outside, and when he does he's just walking backwards between the house and the rocky wall I get my quarry stone, and continues until he's walking in place against a wall that juts out.
I can still talk to him as long as he's not in bed. Sell/buy things with him, get money, ask how the kids are, ask him to follow me. He's just different now.
So, safe to say that whatever or whoever was strong enough to kidnap a werewolf and hold him hostage for a bit, to some cave far from his home, traumatized him.
And I can't really fix him with console commands as it's on the PS4. So he's kinda stuck this way.
Also, fun fact, the VA for Vilkas (and yes, many other Skyrim characters) also voiced Shrek in a racing game. My dark elf is married to Shrek.