[Cold Kitten]

I think the Haku kill happened because it's possible Sanzath and opkiller rolled wolf and so they decided to kill the one person who they knew might be able to read them. Sanz is slightly more experienced than opkiller so I can see him taking the lead in that situation and saying hey let's do this because he knows us so he might be able to get a good read us on because of it

That's why I think opkiller and Sanz might be partners and that's why the Haku kill makes opkiller look more suspicious to me