Okay- I got friends to help me, took nearly 2 hours and I finally beat Othin Fatherstorm, then I did not get credit for the quest! What could have happened. I have had to wait just to have friends willing to help me with that quest because it takes so long. Kings Isle, please give me credit for the quest if you can! Does anyone know why that happened?
I'm not that far in grizzleheim yet (need to do jotun) but i think i can help. Is that place a dungeon? Ex: CRimson fileds, Big Ben, Trial of Spheres, etc. If so make sure you click every question mark to read the dialog . Most dungeons are like that and you wont get credit at all. If not then it was just an unfortunate glitch Try again and if this continues give more details please. Good luck i hope you can figure it out and find more friends to help you
Strawberry12345, Othin Fatherstorm is the Coven leader in Ravenscar. If you have entered the Fortress in the Galacial Waste of Ravenscar and did not beat it, your quest will show him as your quest to be completed. You have to complete this before being able to enter WinterTusk.
Addthatsme, I hope you have been able to get this issue fixed.
Don't let boss-stress get you distracted in areas like this. After a hard-won victory, it's tempting to port out right away because you've already spent hours in the dungeon. But even a single missed NPC chat event, an overlooked yardbird, a missed book quest item, not flipping a lever, etc. will erase all your hard work and progress.
Make sure your friends are on board with the different quests that converge in the dungeon you're in. They should all be going down their own quest checklist to make sure everyone gets their stuff done.
I can't think of many people who like repeating 2+ hour dungeons simply because they forgot to run to the corner and read a book on a pedestal, or missed the NPC chat with the defeated boss that lets them go to the next world or gather the eleventy thousand xp they earned. It's even harder if you relied on friends to get through it, and now they have moved on to Hrundle Fjord without you, and are not interested in doing it again.
For what it's worth, if you do end up having to duel him again, he does drop some pretty amazing and rare things.
Try again and if this continues give more details please. Good luck i hope you can figure it out and find more friends to help you 
