For this conversion, I used the Space Wolf Pack kit, and the Wolf Guard kit, as well as one sword arm from another kit; probably the Space Marine Commander or Command Squad box. I am waiting on the Space Wolves accessory sprue from GW to arrive in the mail. It has the commander back pack that a Ragnar model should have.
Here is how Ragnar's sword arm started. The GW model and the art in the new Codex both show Ragnar with a chain sword. None of the chain swords in the Wolf Pack kit had a pose I liked, so I dug the power sword arm out of my bits box and did some cutting and glueing.
Ragnar is supposed to have fancy shoulder guards. I wasn't too keen on sculpting a laughable imitation with green stuff, and started looking around for suitable bits. While looking over the sprues from the Wolf Guard kit, I noticed this bit:
Perfect! I even had a spare that I had ordered from a bits seller on ebay a while back (thinking ahead/buying stuff I probably wouldn't need). The rest of the cloak has the fur from a wolf's leg that looked like a possible addition to my conversion. It, and the wolf head bit are shown below, trimmed and ready to be attached.
Edit: pictures of the model mostly finished.
Excuse the tissue box with the flowers.